I Guess I Have Deer Mice Now…

by Nicolademee Thu 07 Apr 2022, 11:12 pm

Many of you are familiar with the fact that when you run a rescue people will bring you every type of animal that they find. Well guess what just happened?

I am now sitting in my room very very tired from not sleeping and feeding every two hours with five baby deer mice in my hand. Why? Well, because I am the number one person for random rescues in this whole county.

So, this is where I ask all the questions. What should I know about deer mice, and is there anything in particular I need to look out for? They are about 14 days old on the dot, and some have just started opening their eyes. They were found by a vet employee in her garage and she took them right to the vet without waiting for mom to come back. By the time they called me it had already been an entire day without mom. So, I rushed over and got them to start feeding. By then, it had been too long to take them back and see if mom would return.

They have taken right to formula and are very active and appear healthy. I tried to have my elderly mouse, nutmeg, bond with them to try lactating. But, she’s very done with raising babies, as it has been eight months since she had hers. I contacted many breeders, Rescues, and pet stores but could not get a currently nursing mom for the babies. I was given the next best thing, I guess, which is a mom who just finished weaning her litter. I have introduced her to the babies, but she does not like them at all and does not want to nurse or have anything to do with them.

My main concern is that I am gone for more than 12 hours a day at work. I am hopeful that since their eyes are opening that I can just leave wet oatmeal or applesauce while I am gone and they can take care of themselves until I come home and feed them formula.

I have been doing some basic research to understand more about these guys. I can see the average lifespan in captivity is between 4 to 8 years. I have read mixed opinions on if they can breed with domestic mice, do any of you have solid evidence that they cannot? I run a very full rodent rescue and absolutely cannot afford accidental litters. I also have all of my male mice neutered, are deer mice about the same size as domestic mice? If deer mice can’t breed with domestic mice, then I will not worry about neutering. But, if there is any possibility that they can, I would like to neuter. My amazing vet has neutered 15 mice for me, and only one has passed during surgery.

I am not worried about handling these guys at all or taming them, I have no issues leaving them completely alone besides cleaning and health checks. Are they particular about how much bedding they like? Are they big burrowers, has anyone noticed any specific interests from their deer mice?

One big question: can an adult deer mouse fit through the bars of a prevue 528? It would be preferable for me to integrate all the females into my general mouse colony, but they are housed in a Prevue and I worry they might escape.

Other than that, any general tips or links to care guides would be well appreciated. Thank you all

by cerial Sat 09 Apr 2022, 1:24 pm

Yes a deer mouse can fit through that wire cage opening.

These are between 3/8 and 1/4 and they can easily get in and out. 2 are running on the purple part and the other 2 are hanging on having fun.
https://youtu.be/NuBO-O1C8aA

You need a glass tank with a mesh lid or glass lid that has 1/8" gap at the top. They may hide treats in the 1/8" gap or spider mouse upside down on mesh lids.

You can use old fish tanks or make a large cage out of old single pane wooden windows screwed together and a plywood base. Thats basically my multi cage setup.

They dont chew on the wooden windows for some reason. But I do keep an eye on it.

For bedding I have 3 to 6" of bedding made from thrift store books cross cut to an inch. I shread this then shake it in trash bag(s) to reduce the dust. Then throw 2 " in before spraying it down with 1/5 diluted ivermectin before a bit more bedding on top. They move the bedding all through the cage making nest. I use cardboard boxes and lots of outdoor sticks.
This gives them lots of things to chew, climb, and jump on.

I clean the tank(s) every 2 weeks and everything is thrown out except for the plastic wheels and a few metal mesh things that are cleaned and reused.

The new stuff goes in diffrent spots so they are very exploratory the first day or two after a cleaning.

I have 3 males and never had any of my female fancies pregnant . The fancy sometimes sleep with the deers. Especially if another fancy is being agressive/dominant.

My deers are very submissive to the fancy mice. The fancy are territorial stalking the deers when they go into the 55 gallon cage. The fancy are much slower so the deers can run circles around them. I have albi, freak, and squeaks that sleep with and don't mind the deers. Tan, spot, chip, and my two black mice are all agressive towards the deers.

Deers can do alot of things fancy just cant or wont do. Deers can vertically climb and decend the walls of my cage made out of windows. Which means during cleaning I need to watch for stubborn ones that dont want to go from the one side to the other and may climb as I am pulling stuff out.
Deer mice can jump and drop around 20" and can jump around 3' horizontally. They may hang from there back claws looking down when exploring a freshly cleaned cage.

If you have two of them chasing each other its hard to describe just how fast they are. Lets go with blury.
Here is Fatty with a peanutbutter cracker. She is not only carrying the thing she is running around to find a corner to nibble on it a bit then running to a new spot to nibble some more.

She dropped it after a bit and the others found it later. I should have broke it up before throwing it in.

Point is they are very fast and fearless. When you clean your cage close the door(s) with towels covering the bottom of the doors, vents, and any areas they may get into. You may pick one up inside something or have one just curious and hops out of the tank.

You need to train them now to go inside a mesh cup or jar that you can place a piece of cardboard on the end to move them. If they get out you can be patient and they will eventually go inside this cup after you corner them and give them several minutes to go in on there own.
Treats help train. I use sliced sweet almonds found in cereal as treats generally.

https://youtu.be/5mb9BXB5f94
The cup thing will work for a bit. But they will not like going into a smaller tank during cleaning and will spider mouse etc inside tank making it difficult to open the lid and put the remaining mice into the smaller tank once you get 3 or so inside.

So you may consider having 2 tanks connected with a hose or a divider of sorts in a single tank with (lid on the divider).
I went with a hose and it is small enough they dont chew through it. Anything over 6" they may chew through.
This works for me:

I am able to block it off from the top to clean the smaller tank. Then insert hoses from the bottom (gently pushing anyone hiding inside it out) pushing the hoses up and inserting several so they cant go back down to clean the larger tank.

My 55 gallon long was a former lizard tank I picked up used for $50 on marketplace, my lids are old windows I picked up for free, I picked up the single payne windows for the larger tank for $5, I have 2 connected 10 gallons at $15 ish each and two mesh lids on the top and bottom for another $15 each. Everything else to build including a second 10 gallon put my cost to build everything around $250.

The lids give a 1/8" gap all the way around the top.

But are easily removed or locked together. I have not found a better replacment so I keep using these.

Deers do live for several years and the more floor space you can give them to run and jump the happier they will be. Tanks are perfered. I used those stick tile things on the floor of my wooden tank which made clean up easily and prevents the wood from getting wet. They do not like chewing black "gorilla" tape so that will slow or stop them if they start chewing a area. Other tapes especially electrical tape that I sometimes use to hold down a saucer from moving they love chewing on.

One last thing to touch on is outside deer mice. Once your group is adults they tend to not like other deer mice. Females may accept other females. But generally it is risky. With males there is no exception. The males will kill any new male. If you have multible males they will team up to kill a new male or will fight if a new female is introduced.

I catch mice in my 2 liter live trap. I try to release them the same day. But if the weather is in the negatives I may house them for a few days in the 10 gallon. But I absoultly do not put them in the tank with the others. I have tried two times. A male who I thought escaped when I was cleaning the cage and a female I thought they might be ok with. Both mice were killed quickly.

Deer mice dont mind new fancy mice. But new deers are risky to introduce.

Here is how I introduce my new fancy mice.
https://youtu.be/bkI9w3cJ_Bw

Deer mice can be challenging to keep. But they also make great pets if you work long hours. I am gone 14 hours 3 or 4 days a week so mice have proven to work for me.
They do stick to a firm schedule and I feed them at 7am keeping them on that schedule.

I Guess I Have Deer Mice Now…

I Guess I Have Deer Mice Now…

Re: I Guess I Have Deer Mice Now…