Any good retired mouse enrichment tips?

[J-Lu]

Hi all,

I am adopting 2 mice that just came off study (my colleague is adopting 2, also). Their job was to discriminate between injections of THC or vehicle, and then reacting to some of the current THC-like analogs that humans use, like delta-8, BUTICA, etc.

I worked with them for a chunk of their lives and because they are handled/injected 5 days/week, they are super friendly and love to be pet and scratched. Some more than others.

They got their vet health clearance today and are deemed healthy for adoption, but they’re old. 2 years old. I’m thrilled to give my faves a happy retirement where they are just held and loved. The vivarium where they are kept at has a formal adoption policy for animals coming off-study and have been super helpful.

I found a young-kid’s building set at the barn and made them platforms to climb on. I got nesting material from the vivarium and little paper “huts” that they can chew on, and two different plastic “huts” I’ll alternate because they are not the same. I’ll just keep them on the mouse food they are used to. The vivarium is giving me a bunch (I already have expired food which I feed sparingly to the squirrels). They’ve been on a food-restricted diet and I don’t want to really challenge their gut much. I’m housing them in rat cages so they’ll have a lot of room.

They are 2 males, individually housed for their whole lives and will likely fight if together so I’ll keep them separate but close so they can see each other. So I’d like to keep their environments rich. Of course, I’ll handle them daily because they love to be handled.

Does anyone have anything specific to recommend for the little guys? What have you found that small rodents really like or really don’t like?

[RhythmNCruise]

Well, the one in my tack/feed room seems to like Uckele’s CocoSun oil.
Every day he knocks down the cup that I keep positioned under the pump/spout to catch oil drips. And he poops on the towel that is under the jug and said cup.

You’re welcome to adopt him. Give me your address and I’ll mail him to you if I can catch him.

Just kidding, of course. I refuse to kill him because…well, he’s cute. I do wish he’d stop pooping everywhere and knocking my oil-catching container down though. I cleaned out the entire tack/feed room Saturday in an attempt to deter mousey. I mean removed every single thing from it, cleaned, swept, and then reorganized. I was so proud. Closed the door and did something else for a little while, went back in to get something…damn mouse was like “Oh, hi! Lovin’ what you’ve done with my room!”

But it’s so cool that you can adopt the mice used for research. I had no idea that was a thing, but it makes my heart glad to learn that it is. I hope someone can chime in with good advice. I’ve never had many rodents. Never mice, but we had a pet rat when I was a kid. He was so cool. His name was Templeton (of course).

[moonlitoaksranch]

Toilet paper rolls, hide treats in a wrapped up spinach leaf. Climbing ropes.

[CanadianTrotter]

A wheel that they can run in, tube mazes, flavoured wood chews…

[J-Lu]

hahha!! yes we catch mice in the barn in somewhat more barbaric ways. I also had pet rats we stole from the University breeding program. They were so cool! LOVED popcorn.

Yes, it is a happy thing with our current vivarium as they encourage adoption. I’ve had mice (clueless) and rats before. OMG, the climbing structures i made for these old guys. They really are special mice who deserve a great retirement! So friendly and love to have their faces scratched. I taught them that! But the whole group I worked with is very kind to the rodents. The rodents do behavioral assays and need to be comfy and relaxed and focused on work when it come up.

@moonlitoaksranch, I have boatloads of chewable heavy duty tubes from the vivarium. They are all set on this front. Thanks!!!

[LookinForSpace]

I’d introduce at least some fresh food into their diet. Fruit, vegetables, grain (bread, crackers, seeds) would be a good addition. And, of course, Cheese!!

[J-Lu]

The vet mentioned Cheerios and we’ll start there (because I love Cheerios and have that in house), I can introduce some carrots but I’d be wary because they never had them before. They’ve had laboratory chow that meets all of the requirements for lab mice. That’s it. Thanks!!!

[LookinForSpace]

@J-Lu

The vet mentioned Cheerios and we’ll start there (because I love Cheerios and have that in house), I can introduce some carrots but I’d be wary because they never had them before. They’ve had laboratory chow that meets all of the requirements for lab mice. That’s it. Thanks!!!

Yeah, probably no harm in going slow when introducing new foods.

But as for the sentence that I bolded above, for humans, the same can be said for army rations, but given a choice, I doubt any human would willingly subsist on nothing but that for their entire lives. If they’d been raised solely on army rations in some alternate universe, I’m sure they’d appreciate the option to try new foods in adulthood. Then again, given how picky some people are, maybe they WOULD decide that new foods were NOT something they wanted to even try! LOL

[PintoPony]

Take crepe paper and twist it between your fingers to form “twine”. String Cheerios on the twine and tie it up in their pens.
Crepe paper twine is great because it’s strong enough to hold lightweight items up, yet weak enough that it can’t hurt an animal if they somehow manage to get tangled in it. It breaks super easily, is easily chewed thru and basically dissolves if it gets wet.

I used to work with monkeys in a lab setting and we used the “twine” quite a bit. We used natural color so there was no concern about dyes.

We also used food grade scents quite a bit. Spritz a bit on some bits of cardboard and scatter them around the pen.

Ice is also something that is easy to use for enrichment. Not sure what mice would think of it but a few pieces in a little dish would be simple and harmless.

[S1969]

I kept my first lab rat in college, so I get it. Mice would have been easier. I had a big fat white rat in a sorority house. It was not an enriched life for him, unfortunately. But beat the alternative, I guess.

I think they will love Cheerios and carrots, and you can see how that goes and introduce other fun things a little at a time. I belonged to a group for some years that met in an old house and one year there was a kitchen mouse…so we tested out various foods to see if mice really prefer cheese. And nope - it was cheezits and peanuts over cheese EVERY time. We conducted quite a controlled study, moving them in different places, changing the order, etc.

I think anything you give them will be fun - changing their environment will be the most enriching thing, even if they prefer one thing it will be good to introduce others (e.g. cardboard tubes, but also boxes, maybe pieces of wood, plastic toys). Do they have a wheel?

[trubandloki]

Fabric hammocks and such are always fun.

I had rats for a long time. Cheerios are a huge hit so start with those for sure. Baby food is also a fun treat. The baby snacks (cheerio sized things) were popular.

[Marla_100]

How about giving each a tiny, furry teddy bear type stuffy toy so they think they have a friend.

I have raised many wild babies and so many have loved stuffy toy friends. and even used
a real rabbit pelt as their favorite blankie.

Your little meeces need emotional contentment
and enrichment due to living a solitary working life.

I love this thread and hats off to J-Lu for having a good heart.

[LookinForSpace]

Puhleese give them a piece of apple or Cheerios and video their reaction, then post it here.

[DawnJL]

I had pet mice as a kid and was a caretaker of lab mice one summer at university. A few years ago I found a 2 week old (furred eyes closed) white footed mouse in one of my run-in sheds. Poor wee thing was huddled against the wall of the shed. I hand reared him with goat’s milk using a cotton swab to avoid risk of aspiration. A year later I found another similar age baby white footed mouse near one of the run-ins while doing chores. I successfully hand raised her too. The male (born early July 2020) is Pippin and the female (born July 2021) is Merry. I keep them in separate habitats.

I feed them a combination of a high quality lab mouse ration, a mixed pellets/seeds mix for small rodents, and supplement with additional seeds -pumpkin, sunflower, flax are particular favorites, fresh fruit --blueberries, blackberries, raspberries, and pieces of strawberry are enjoyed greatly. Small pieces of carrots, peppers, and spinach have also been enjoyed. Both also like a small dollop of goat’s milk yogurt a few times a week. Obviously, adding to your retired lab mice’s diet should be done gradually and with close observation.

I put food out in a bowl and also place the fruit and seeds around there vivariums for them to find. They both cache food in various spots. I’m not sure if domestic lab mice will have the same drive to cache food as these wild mice do.

Link to Video of Pippin eating a raspberry

I use shredded paper bedding and add some cotton fluff and clean straw for them to use to make nests. Pippin, the male, is more of a nest maker than Merry, the female.

I have several different hideouts, tubes, ramps/ladders made from wood (some with bark on) which I swap out to vary the layout and stimulate exploration. They enjoy climbing and exploring. Both also really enjoy their wheels. (Study of mice --and other animals— using a wheel in the wild!) This is the wheel I have. It is truly silent and is easy to clean.

Edited to add video clip of Pippin the first time I gave him a raspberry.

[gailbyrd]

Meal worms, the kind you get at a fish bait outfitter. Mice LOVE those things. Back in the dark ages (1980’s) I was working in a lab that had captured wild mice of different genius to study their MHC complexes. Had a hard time adapting them to the animal facility environment but between the meal worms and bird seed (especially black oil sunflower seeds) along with pelleted rodent diet, they thrived well enough to breed and produce lots and lots of babies. And the lab born for many generation mice LOVED the meal worms as well. We always supplemented the breeders diets with meal worms.

Good luck with your old guys and may they live to the ripe old age of 4.

[ShenanAnna]

Studies show that monkeys reared in labs do much better, emotionally and maturity-wise, if they have a terry cloth “mother,” a stuffed animal, really. They cling to it like a real mother.

[J-Lu]

Thanks everyone!!!

These mice are coming off study as our Institute is moving vivaria. And, the old vivarium moved to a new building across the street. That said, I’ve accumulated lots of their rodent food (which sadly, I also feed to the squirrrels), lots of cardboard huts, lots of nestlets and the vivarium is giving us a package of cages and things (which I already accumulated for travel) and nylabones for them to chew on. Another staff member gave me two woodblocks. I’ve already accumulated static rat cages (disposable and plastic). They don’t use static cages and their new facility and we are able to take much. At this point, I can easily rotate the enrichment and environments when I barn-sit. Both places have dogs and cats and I’ll put them in the temporary static plastic housing with sealed lids.

Today were were officially cleared by the IACUC committee to take them home! The vet was amazing, and said we could always reach out to her for questions, even when our “official” mice go to the new vivarium.

Man, I hope the mice have 9 lives, because I have enough enrichment to rotate for 9 mouse lives!!

[J-Lu]

I love your video of Pippin! And love the name!

I do worry about the GI of these mice. They came from a national/international distributor, have only ever lived on Rodent Diet 1053. Their gut microbes are only used to that and any other food would have to be slowly introduced. But you’re mice put berries on my radar!

These guys were food restricted until now (up to 2.8 g pellets/day plus sugar treats during their run), and I’m not sure how they’ll behave. I’ll initially give them three times that amount to see what they do. The vet thinks they might have a formed low caloric habit but I know one previous mouse coming off study gained 10 grams, which is a lot for a mouse. We’ll see!

[pony_baloney]

Wouldn’t goats milk have enough beneficial probiotics to help transition to real food?

[J-Lu]

I don’t know. I’m not sure what probiotics work for mouse gut function.