My baby mouse foundling

Question
Hi.
Just yesterday i found a small mouse in a parking lot now 2 feet from where my tire stopped! The thing wasn't moving so I tapped it with my toe and he squirmed. I brought him home and placed him in my vacant gecko tant with coco husk as flooring. I tore up some napkin and added it to the cage. After reading on some websites I learned that he needs the dark, half water and half can milk feed, and since his eyes are open I put some seed in with him. I am not sure exactly how old this critter is. From what I've read of ur articles I would say 2-3 weeks but on another website I saw that he may be only 1-1/2 or 2weeks. He ate a bit of bird seed and does drink the milk when I offer it (like half a cc each time if that). I've placecd a towel over his tank to help keep him warm (I heard it should be 80 F). He is quite active when disturbed (besides that he stays curled up). What I'm wondering is what kind of mouse he is, How to tell the sex, If i should release him after caring for him, and if I am allowed to keep him anyway♥... Also if I am doing anything wrong I would love to hear it! I have no pics yet but if you need one let me know! Thankyou for your time and sorry for all this rambling (I thought the more info the better :s )

Answer
Dear Donja,

First of all, thank you so much for caring and rescuing the little mouse pup.

Mouse eyes open on about day 14, so he is over two weeks old. If he has eaten some seed, then he is closer to three weeks old.  Actually cow milk isn't the usual recommended formula for baby mice. There is so much conflicting information on the web, and I'm sure some people have had success with it, but by far the most common formula to use is kitten milk replacement (KMR); soy milk works; and one vet I know absolutely swears by possum milk replacer.  KMR is kind of expensive to buy powdered if you only need a tiny bit; if you decide to go that route, buy a can and freeze it in an ice cube tray to thaw one small cube out at least once a day. You won't need to give him milk for much more than a week anyway.

You can certainly keep him; he'll be a great pet if you just hold him a lot when he's little (if you are drop feeding him, that's already built in).  You can sex him with the following chart: though his testes will not have dropped yet if he is a boy, you can look to see if s/he has nipples, because boy mice don't have nipples. You can also compare the genitals with the photos but seriously, they look almost the same!

http://www.thefunmouse.com/info/sexing.cfm

For species, assuming you are also from the US, here are links to the most common mouse types here:

Here are descriptions of the Deer Mouse, White-Footed Mouse, and House Mouse:
http://www.thefunmouse.com/info/species.cfm

Individual pages for mouse species:

Deer Mouse:
http://www.wildlife.state.nm.us/education/wildlife_notes/documents/NoteDerMouSm....

House Mouse:
http://www.arkive.org/house-mouse/mus-musculus/info.html

Yellow Necked mouse:
http://www.arkive.org/yellow-necked-mouse/apodemus-flavicollis/

Wood mouse:
http://www.arkive.org/wood-mouse/apodemus-sylvaticus/

Harvest Mouse:
http://www.arkive.org/harvest-mouse/micromys-minutus/

HAVE FUN!

squeaks n giggles,

Natasha

PS photos are always welcome : ))