A List of Safe Woods for Rats and Mice (And Unsafe Woods to Avoid)
Branches and wooden toys are a brilliant way to enrich the in-cage life of rats and mice. They’re great for encouraging climbing and clambering around, and offer a really nice range of smells and textures to interact with. They are also good for nibbling and gnawing – and there are few things rats and mice enjoy more than finding something to gnaw on.
The content of this article was contributed by guest author (and rodent wrangler extraordinaire) Beri Instone
But before we start – some important safety / legal notes.
For Pet Safety
Make sure you are 100% sure what species the branch is from before giving it to pets (see the safe woods list below). It is ultra-important to know exactly what you’re giving them, so you can make an informed decision on safety. This means that simply grabbing a branch from the ground is a bad idea. Also, unless you’re very skilled, avoid trying to ID what species a tree is in winter (there will be no leaves to help you out, and many of the safe species do drop their leaves).
Avoid trees which are near heavily used roads (pollution) or have been sprayed with chemicals.
For Your Safety
Before collecting any branches, assess the situation for safety. Is it safe and appropriate to collect from that tree? What tools are required, and do you know how to use them safely? Do you need personal protective equipment? Where necessary, seek assistance from someone trained in pruning. Do not climb trees to obtain branches. Be aware of your own safety and that of others around you.
Check the foraging laws of your country/area, as some trees are included in these types of legislation. And always get permission from garden owners before pruning their plants.
For Tree Safety
For the health of the tree, branches bigger than the size of your index finger should only be pruned off in the colder months of the year. This is because by pruning a branch you’re basically creating an open wound. Think of tree sap like human blood – in warmer growing months the sap is ‘up’ [technical term], and any infection is more likely to spread. In winter the sap retreats, meaning the tree wound can heal more safely.
It’s also important that when you cut a branch, you make the cut at an angle that isn’t horizontal to the ground (as vertical as possible is best). This ensures any rain will drip off, rather than collecting and rotting the tree.
Foraging for enrichment is fun, but it should be done in an environmentally conscious way; don’t leave a path of destruction behind you.
Drying Out Wood and Making Safe
You shouldn’t just give newly cut branches to your pets. First, they need to be made safe (any bugs or parasites killed) and then dried out.
The best way to clean the branches at home is to use wet heat:
- Put your branch in a bath or sink, boil a kettle, and gently pour the hot water over the branch. Be careful to avoid splashing yourself or others.
- You then need to dry the branch out to the point that the sap goes from being a green layer under the bark, to turning brown too. How long this takes depends on how big the branch is and how warm your house is, but 2-6 months is a good guideline.
Some people use bleach as part of the cleaning, but remember wood is a porous material and so properly rinsing it afterwards is nearly impossible. On balance, exposing your pets to bleach is likely to be the more dangerous option. We feel that if bleach is needed to clean a branch, then that branch wasn’t safe to collect for pets in the first place.
The decision on whether to remove lichen is purely aesthetic. It’s not dangerous for your pets to nibble, in fact most times quite the opposite as it’s historically a pretty nifty food source. Extra enrichment!
Much info online advises freezing wood to make it safe, but this does practically nothing. In many areas of the world, trees and parasites have adapted to sub-zero conditions as a natural part of their life cycle.
Some sources alternatively recommend using the dry heat of an oven. We don’t suggest this for two reasons. Firstly, you’re limited on branch size in terms of what you can fit. Secondly dry heat can change the cellular structure of the wood, cracking the outer bark. Cracks in bark = easier for pee and poo moisture to permeate in later = branch gets very stinky very quickly = a lot of work for nothing.
Fine little twigs are usually safe to be fed straight away, or after about a week drying out in the home. These are the sort of size that won’t hold the weight of a mouse, much less a rat, but they are great to just put on the substrate as a nibble toy. They usually get completely demolished before too long.
Cleaning Twigs and Branches Between Uses
Rats and mice do tend to pee everywhere, so wooden toys and branches in the cage will get dirty. To clean them you can do something similar to the initial cleaning above with soaking and then leaving to dry, although if the bark has been nibbled off, the less waterproof inner part of the branch will take longer to dry.
Many people find it more effective to just wipe clean the surface of branches. This removes the worst of the dirt, but doesn’t completely strip scent marking away, meaning your rats/mice won’t go wild with re-marking.
If you have access to outside space then a really nifty thing to do at less frequent intervals is simply to leave the wood outside for a bit, to allow smells to dissipate. A couple of weeks outside and then drying inside and you’re good to go!
Which Types of Wood Are Safe for Rats & Mice?
Not all types of wood are equal, and some can be toxic to our pets so it is important to know which types are safe and which aren’t.
There are two main categories of wood. It’s important from a rodent enrichment and safety point of view that you understand the difference:
- Hardwoods are grown from trees with normal flat leaves. These trees grow slowly, which results in harder and stronger wood, hence the name.
- Softwoods are grown from conifer trees, which have needles instead of normal leaves (think Christmas trees). These trees grow really quickly, so are the backbone of the commercial timber industry.
Hardwoods are the category we focus on for tree species that are safe to use with rats and mice.
A general rule of thumb is that wood from trees which are listed as safe for rabbits to eat are safe to give. Rats and mice are omnivores like people, and have much more robust digestive systems than rabbits. Additionally, they’ll only really be nibbling the wood, rather than scarfing it into their faces as a meal like rabbits do.
However, when looking at any lists of suitable woods online, it is very important that the list gives the Latin names of the tree too. A Latin name refers to a specific species of tree, while common names vary internationally and may refer to a safe tree in one country but an unsafe tree in another.
Our Favourite Woods to Give Rats and Mice
- Apple (Malus domestica) – super tasty wood, will likely not last very long before chewed up
- Hazel (Corylus avellana) – another tasty tree, but big branches last well
- Ash (Fraxinus excelsior) – particularly great for challenging rats as small diameter branches are exceptionally strong, and are famed for bending rather than snapping. Branch wood is very smooth in texture, so easy to clean.
- Birch (Betula sp.) – mice and rats find birch super tasty, I (Beri) try and always have a few twigs in the substrate for nibbling
- Hawthorn (Crataegus monogyna) – thorns should be removed for safety, although harvesting the new year’s growth from hedges results in twigs with far fewer thorns on than from trees. Very tasty.
- Elder (Sambucus nigra) – lovely texture to the bark, so great for rats who need a bit more grip
- Alder (Alnus glutinosa) – one of the few deciduous trees which produce cones, for extra enrichment
- Willow (Salix sp.) – commonly sold commercially as nibble twigs, you should take particular care with these species that the wood is fully dried out before giving it to pets.
- Cherry, plum, peach (Prunus sp.) – these woods can have a fabulous texture for climbing, and aren’t very palatable to mice and rats, so a big branch can last years once dried.
- Buddleia (Buddleia davidii) – lots of people have these growing in their gardens as the flowers are excellent for butterflies. Try to use the older woody growth rather than the newer green growth.
- Beech (Fagus sylvatica) – forageable branches are more likely to be mouse-size than suitable for rats.
- Hornbeam (Carpinus betulus) – loved by squirrels (also rodents) for the tasty bark, but can often have fungal infections. Extra tree-health care needs to be taken with these.
- Lime [UK] or Linden [US] (Tilia sp. and Tilia x europaea) – takes longer than average for branches to dry out, and often has a high parasite load
- Rowan, Whitebeam (Sorbus sp.) – many of these trees don’t grow very big, so will be more suited for occasional use with mice, rather than for rats, or with high frequency.
- Bamboo (Bambusa vulgaris)
Unsafe Woods That You Should Never Give to Your Pets
Toxic broadleaf trees which should never be given to rodents:
- Horse chestnut
- Orange / citrus
Please note this is not a complete list. Rather, it focuses on the woods commonly asked about on rat care forums. If you are not certain a wood is safe for your pets, or if you are not certain of the ID of the tree, do not use it.
Also, don’t use man-made “woods” like plywood, MDF, laminate etc. as they contain glues or chemicals.
These trees are not suitable to collect branches from for enrichment purposes. Trees and woods in this category include pine and cedar.
This is because the wood is incredibly oil-rich and the bark has a very different structure to hardwoods. The tree uses the oils to stop parasites, infection and other harm from coming to itself. The oils in the woods contain compounds called phenols which can be toxic to rats and mice, and it is not possible to safely treat them at home.
So What About Softwood Shavings as Substrate?
The difference here is that commercial operations can use MUCH higher heats to treat the wood than is possible at home. And these very high heats can remove the phenols making the wood safe. This is why it’s important to make sure that any softwood shavings you buy have been heat treated (e.g. kiln dried) rather than being raw.
In addition to being heat-treated, any wood shavings that are going to be used for rats and mice should be dust-extracted. Dust, from any source be it wood or paper, is bad news for rodent respiratory systems which are highly sensitive.
The best wood-based beddings are the large kiln-dried and dust extracted flakes originally sold for use with horses.
But All My Commercial Rodent Toys Are Made From These Softwoods, Are They Safe?
Trees which are going to be turned into timber go through a completely different set of processes to anything we can do at home. All of the moisture (both water and oil) is removed from the wood to make the product safe, cheap, and easy to manufacture.
So, pine toys from pet shops and home-made toys using pine from the hardware store are generally safe. Wood toys made of java wood (coffee wood) and balsa are also safe.
Just a quick comment to tell you that I think your website is incredibly well done, full of great infornative, well-organized goodness for anyone feom begginer to experienced owner. Thanks for the obvious hard work you put into informing the pet rat (and mice) comunity!
Thank you for such a wonderful comment 🙂 We are very happy to see people appreciate what we do here 🙂 You made our day!
Thank you for making this guide! We found a lime/linden branch today, but weren’t sure if the high parasite load that you mentioned will be an issue. Can we sanitise it by pouring boiling water over it, or does it need some sort of additional treatment? Also, for any type of wood, do you prefer to leave the bark on or strip it off?
I’ll forward your question to Beri for a more expert answer. But I don’t think there is a different treatment, it’s more a case of ensuring the cleaning and drying steps are dome thoroughly.
So feedback from Beri is she’d have concerns about how long a found branch has been on the ground. But if you are comfortable around that, then the higher parasite load means stripping all the greenery, and then being very thorough about cleaning and drying. As always, I follow a rule of if in doubt don’t use it, as there are lots of other options for engagement.
Thanks for the additional information! The branch was still (barely) attached to the tree, but looked like it had died a while ago, so we’ll discard it to be safe.
With regards to bark in general, definitely leave it on. Several reasons for this
1) Most bark is incredibly difficult to remove
2) Most rats and mice absolutely adore stripping the bark themselves, so you’s be going to a lot of effort and blood, sweat, and tears and would end up with a less enriching product at the end of it.
3) If the bark is easy to remove then the branch is probably diseased or already well on they way to decomposition. It should be discarded and not used for caged pet enrichment.
Given your two questions come together about a branch you “found” I would leave it.
We need to know whether shagbark hickory is safe. We live in the north east US.
Hi Michelle, I’m afraid I don’t know (I”ve asked Beri, but she’s based in Europe – I’m in Australia!). I’d suggest checking with some knowledgeable US rat keepers, but the rule of thumb is if in doubt don’t use it.
Your question is covered in the article, specifically this section:
“A general rule of thumb is that wood from trees which are listed as safe for rabbits to eat, and trees which people can safely eat the fruit of are safe to give. Rats and mice are omnivores like people, and have much more robust digestive systems than rabbits. Additionally, they’ll only really be nibbling the wood, rather than scarfing it into their faces as a meal like rabbits do.
However, when looking at any lists of suitable woods online, it is very important that the list gives the Latin names of the tree too. A Latin name refers to a specific species of tree, while common names vary internationally and may refer to a safe tree in one country but an unsafe tree in another.”
So first steps for you would be:
1) Find out the Latin name of the tree, to be clear that everyone is talking about the same tree
2) Look on any local rabbit-safe forage lists to see if it features. Looking on lists of trees safe for degu is also appropriate, as that community is similarly science-minded and high-forage diets are promoted as best practice.
3) Depending on results there, you may need to do further research into if it’s safe for human consumption or not. And/or if any parts of the tree are used for low-concentration health remedies.
Hope that helps.
Hi, you guys are so informative! I have looked everywhere to find what woods are safe to build toys and cage accessories out of for mice. I see many that they can chew on branch-wise but I’d really like to know what kind of lumber is okay, even as far as building a cage or extra levels. Seems that hardwoods would be fine? But are some better than others? Thanks!
I use pine dowel for perches – although pine branches (raw pine) are not safe, the pine dowel and planks sold in hardware stores are fully heat treated and dried which removes the toxic chemicals. I wouldn’t use any wood to build a cage though – they can chew out! I also limit its use in shelves as all wood will soak up pee with time and get stinky. So I only use wood for removeable accessories I can scrub!
Not all hardwoods are safe – but those on the safe woods list above are. It will depend on what lumber is available in your area (round us it is mainly species of eucalypt, so not suitable)
Just a query, but I’ve read on multiple other pages that beech wood and all fruit trees with stone bearing fruits (prunus genus) are toxic? But you have them down as safe? Can you confirm please
My understanding is they are toxic to rabbits, who actively eat the wood, and that’s led to them also being placed on toxic lists for rats who generally don’t and have different digestive systems. But I’ll ask Beri to come and elaborate!
Hello Kirsty – apologies for the delay,
I will go through this one at a time:
1) Trees with stone-bearing fruits. These trees having toxic wood is categorically incorrect. It is often the case (especially online) that people hear information slightly wrong, and then pass it on slightly wrong in another way themselves, and it snowballs into something completely incorrect. Sort of like a game of Chinese whispers!
The very inside of the seed (stone or pip) in many fruit trees (includes Prunus sp. but also others like apple) contains small amounts of amygdalin. During digestion the body takes amygdalin and converts it into cyanide. Everyone knows cyanide is toxic.
1) It is only the inside of the seed/ stone/ pip that contains concentrated amounts of amygdalin – this is why the fruits from these trees are perfectly safe to eat.
2) Toxicity is a threshold situation – a small amount isn’t going to cause any harm to even a mouse-sized pet.
3) Amygdalin is very bitter and not pleasant to eat.
This is why there’s the folk saying that a human child eating a cupful of apple seeds will die – it’s based on the factual presence of amygdalin, but somewhat twisting the scientific details!
So in practice, your rat/ mouse/ other rodent would have to eat a huge amount of the wood in a very short space of time for it to be a problem. And I really do mean a large amount. Neglect situation with no other food present and maybe then they’ll try and eat the wood. Most properly cared for pet rodents will have a little nibble, go ‘bleurgh, this is disgusting’ (except for apple wood, where the seeds also have amygdalin but the wood tastes nice, because there’s no amygdalin present in it) and leave it and tada, then you have an enriching toy that will last practically forever because they won’t be chewing it.
2) Beech is a tree, like oak, that has high levels of tannins. These are the chemicals that are found in foods like tea and red wine and coffee and so on. Horses are not really able to digest tannins at all, so even a small amount of beech is poisonous for them – and horses being big money means beech will be added onto lists of toxic plants online with no further detail. Humans are able to digest small concentrations of tannins (see e.g. tea, coffee, red wine), but not really high levels (e.g. a human eating a raw acorn is very dangerous and you should go to A+E).
Rodents though? Rodents are different. Especially rodents who have evolved in areas where extensive broadleaf woodland where species like oak and beech are abundant (squirrels, mice, and rats). Rodents are comparatively AMAZING at digesting tannins. Everyone knows that squirrels eat raw acorns? Mice and rats can too. The wood is nothing in comparison for them – just don’t go and have a nibble of it yourself!
Of course if you’re still not happy with the above then you can completely avoid these species. But do it for correct science reasons. And also remember that all enrichment comes with some level of risk, that’s part of being alive and having an enioyable life.
Hello Beri. This seems very interesting and I’m curious if you could link your sources to this information? Thanks in advance.
I peeled some birch bark from a big old branch that had come off our tree during a bad storm. It is just the bark. I don’t think pouring boiling water over it would be good. Can I possible microwave it to treat it for parasites and mites etc.
Doing the boiling water method for bark is perfectly fine – and remember, most branches you do this to are going to still be covered in bark too. There is nothing different about a piece of wood that is only bark in this regard. Putting it in a microwave for long enough to have the desired effect risks burning and/or igniting spots of the bark.
The artical talks a lot about wood from a personal or home owners perspective. But im wondering about a list of lumber yard woods that are safe for mice to have in there cage.
I use 2×6’s in my mice cages. My mice have a tendency to pile up litter in there food and water dishes if they are ground level. But when i add a layer or two of 2×6 and put the dishes on top of them (so they are above litter/ground level), nearly all of them have stopped.
Of course stores have many different kinds of lumber style wood, which can vary in region. But is there a list of those kinds that are safe vs not safe?
Timber/ lumber (same thing, EU vs NA) is a completely different topic to the article, which is why it wasn’t covered. This has nothing to do with personal/ home-owner’s perspective, rather the safety considerations and what you can then offer enrichment-wise.
To quickly answer your question, the best option for flat timber is aged pine, while you definitely shouldn’t touch any man-made woods (MDF, chipboard etc.).
There will be an article coming out soon on better ways you can provide enrichment to your mice in your cages than just flat shelves. Plus my draft pile also contains ideas on articles which cover how to most effectively feed and water your mice. So please stay tuned!
Does anyone know if Schima Superba is a safe wood for mice? It’s a type of evergreen used to make wooden craft materials. Or would pine be safer? I’m always wary of pine, as I’ve heard repeatedly that only kiln-dried is truly safe, and I err on the side of caution.
You’re absolutely correct that only heat treated (“kiln-dried”) pine is safe when talking about substrate on the floor of the cage. The last section in the article covers pine in for non-substrate uses:
To expand, pine logs that is being used in construction will have been left for several weeks if not months to dry. Usually first in the forest (if you ever go for forestry walks you should recognise the piles of logs frequently dotted around), and next inside warehouses. All timber that is being used for construction will go through this ageing process to remove the moisture. From a rodent health pov this achieves the same health benefit as heat treatment, just longer and slower to get there – think of running a race vs walking it.
I’m afraid I can’t comment on the safety of the tree species, Schima Superba, you mention, as I’ve never heard of it and google isn’t throwing up any useful resources. For rodent safety the dried wood also needs to be safe to nibble, not just breathe near. Aged pine timber is safe for both existing near and for nibbling. If you want to do your own safety research you will need to see whether it is safe for any herbivorous animals to eat (good), and if the species is used for any natural medicines (bad).
is lichen safe for mice to nibble on? (not sure what this stuffs called but it grows on a lot of trees here in Alberta. It isn’t wolf lichen)
Thanks for all the info! I just cut my buddleia and I’ve save some of the woddier bits for my mice! Can I just double confirm that these are safe after treatment? I’ve seen some places say it’s toxic for rats but not a lot of info on mice, I know they’re not the same but they’re similar and so I’m hesitant since there’s not a lot of places aside from here that confirms that buddleia is safe! I’ve seen for degus its not safe too due to antibacterial properties in the wood that gives them diorrhea but again, not the same animals haha. So I just wanted to be super sure, thanks!
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