Reptile & Amphibian Forums

my question's probably been answered already in the below posts, but i just want to be sure. as i said in my earlier post, i was worried about fleas. well, here's what's happened with my situation in the last few hours. originally, i had a breeding trio - 1 male and 2 females - in the same 20 gallon tank. i later introduced 2 more mice(sexes unknown) into the same tank. almost immediately i noticed what i perceived as hostility within the group. members of the breeding trio would go up to the other 2 and 'bite' or 'swat' at them. it seemed apparent that their extra company was not wanted. i made no attempt to separate them, however, figuring they would all eventually settle down. the 2 newcomers retired into corners of the tank and basically withered away. i discovered them later stiff as a board! the fleas or lice(whatever they were!) seemed to centralize on these 2 mice. the remaining trio, however, appear fine and healthy. my question is this: is it best to leave a breeding trio or quartet just as they are? is oppression what ultimately led to the death of these mice? there was no cannibalism, the mice just died. i froze them, but is it better to just toss them rather than feed them to my snakes? i am quite the novice when it comes to breeding mice and any input or valuable insight i would very much appreciate.

thanks!

greg

Hi Greg,
It sounds like you have a nice setup going on.. A large tank that's not overcrowded, etc. Sorry to hear that your little group is not doing as well as they should be.

Were the newcomer mice purchased from the same place that the others were? Or at the same time? There's certainly the chance that they were/are ill.

You mentioned that the 2 new mice were of unknown sex. Even though it doesn't sound like these mice were killed by their cagemates (not directly, anyways... I guess stress could have caused it - but how long were they together for?). It is worth mentioning that male mice should not be kept together -- especially not when females are present.
I have had success keeping brothers/littermates together when raised with one another from birth. But that does not apply to males who are allowed to smell and see, let alone live with, females. Males are very territorial and will fight to the death, particularly in the presence of girls. One boy per cage is more than enough to "service" a dozen females or more. And a very happy mouse he will be.

I've rarely had problems introducing females into an existing group. In general, mice are tough little animals and can hold their own against even very dominant individuals. Females are usually very docile with each other. During the initial "where-do-you-belong-in-my-social-hierarchy?" phase, Some spats will occur. Sometimes even leading to minor injuries. But in the case of my rodents it has never been a life-or-death situation.

Fleas will not hesitate to bite mice, but they generally won't completely infest a cageful of rodents. So, I suspect that your critters have lice or mites. lice can be treated with a topical such as kitten flea powder or Advantage for cats (you must check with a vet - most are happy to consult over the phone for free - for the proper dosage. It will be a very, very tiny amount) Mites are a bit harder to get rid of since they burrow beneath the skin. The only cure I have found is dosing with Ivermectin. The smallest animal I've used this treatment on is rats. So I cannot give a safe dosage for mice. I can tell you though that this stuff WORKS if mites are to blame. (FYI ~ Mites are usually accompanied by hair loss, itching, weight loss, and increased thirst/urination; whereas lice don't usually involve the latter 2)
If fleas are to blame, I have heard that a natural deterrant is lining the bottom of your cage with cedar shavings. These are, of course, a big No-No for everyday rodent bedding. But, if you make sure that your cage is well ventilated to reduce the risk of respiritory infection, the smell of cedar in the cage for a few days can be enough to make fleas leave the scene.

Which reminds me, if you are using any type of softwood bedding (pine, cedar, etc..) currently, then that in itself may well be the cause of their itching. Cedar is the most harmful, but even the ever popular pine is irritating to rodent skin and respiritory systems. Aspen and paper-based beddings are probably among the safest out there right now.

Are you attached to these mice? I mean, are they pets, or are they just breeders who will eventually be food?
If they are pets, by all means, take the time to treat them and get them better. However, if they are feeders, I'de suggest putting them out of their misery now, rather than later if indeed they do have parasites. It sounds like you just got a sick bunch, which happens, unfortunatly. It can be difficult and time consuming to medically treat mice. I have handraised litters and cared for many sick mice, and rewarding as it is, it's not particularly easy. If these guys are going to be a meal sometime in the future, I would end it for them now and start fresh with healthy young adults.

If you have used any pesticides on these guys, DON'T feed them to your herps! This could cause problems. If you treat the cage with a powder or treat the mice, wait a good long while before you feed them off.

External parasites that bother mice will not affect reptiles, since they feed only on warm-blooded creatures (and are often species-specific). But certain internal parasites can be transmitted. For this reason, I suggest freezing any feeders from this bunch before giving them to your herps.

Sorry this was so long! Hope this helps.

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Herps~
1.0 Ball Python (Squeeze)
1.0 Amel Corn (Ashbury)
1.0 Tangerine Honduran Milk (Diablito)
0.1 Brazilian Rainbow Boa (Nyoka)
1.0 Bearded Dragon (Spike)
0.0.1 Treefrog (Keropi)
0.0.3 African Dwarf frogs
0.1 Red Eared Slider (Shelly)

Dogs~
1.0 6 y/o GSD/Mastiff/Shar-pei (Max)
0.1 7 y/o Pit bull/lab (Missy)
0.1 2 y/o Chow/ACD (Sierra)
1.0 6 y/o terrier x ??? (Tripper)

Cats~
1.0 6 y/o black DSH (Salem)
1.0 3 y/o Tuxedo DSH (Felix)
1.0 8 y/o Orange DLH (Benji)
0.1 10 y/o black tabby DSH (Peppermint)
0.1 3 y/o Calico DSH (Abby)
0.1 2 y/o W&B DSH (Bob)
0.1 2 y/o B&W DSH (Figaro)
0.1 2 y/o B&W DSH (Jasmine)
0.1 2 y/o Calico DSH (Raja)

Birds~
1.0 Alexandrine (Alex)
1.0 Yellow Collared Mini Macaw (Baby)
1.0 Indian Ringneck (Rosie)
1.0 Sun Conure (Tango)
1.0 Red Lored Amazon (Rocky)
0.3 Peachfaced Lovebirds; Lutino (Tweety), Dutch blue (Delilah), and Pied (Iago)

Rodents~
0.1 Syrian Hamster (Amelia)
0.2 Dumbo rats (Elizabeth & Cheddar)
0.1 Het Beige Chinchilla (Zion)
1.0 3-legged Black TOV Chin (Smokey)

Rabbits~
1.0 Tri colored Mini Rex (Buster)
0.1 chinchilla French Lop (Martha)

Fish~
29 Gallon tank with Neon tetras, a betta, a guppy, 3 frogs, 3 sand loaches, 2 platies, 1 dwarf gourami, and a cory cat.
Plus 3 5-gallon tanks with one betta each.

i appreciate your concern. man, you have a lot of animals! i'm getting there myself with 22 snakes and a cat. LOL! you answered another question i had in my mind - are mice territorial? i figured they were. i do use aspen bedding. i'm well aware of the problems associated with cedar and pine. i'm breeding the mice to have pinkies for my snakes. this is a first time thing for me. i'm doing it because of lack of any other choice right now. i'm out of work, my regular supplier doesn't have anything and buying mice at the pet store every week gets expensive! as i said, my breeding trio is doing fine. one of the females is pregnant for the second time. i just hope they don't try to eat the babies again. i noticed that the 'bugs' on the 2 mice that died didn't 'jump', so maybe they were lice. are they still safe to feed to my snakes after i freeze them? you seem to have a wealth of knowledge and i thank you for sharing it with me. good luck and long life to you and all your pets!

sincerely,
greg

snakes:
1 Eastern Hognose
1 Eastern King
1 Northern Pine
4 Eastern Garters
1 Eastern Garter(blue phase)
1 Western Ribbon
1 Checkered Garter
1 Western Hognose
1 Eastern Milk
1 Texas Rat
2 Corn Snakes
1 Bull Snake
1 Florida King
1 California King
2 Mole Kings
1 Black Rat
1 Timber Rattler

Cats:
1 Seal Tortie Point Siamese

I would take your three healthy mice out of the tank, clean the tank completely, throw out all bedding that was in it, throughoutly wash the toys, hides etc (unless they are all disposible, then just toss them out with teh bedding). use a 1:10 bleech solution to clean everything. Rinse well and let ventilate for a bit. THen put the mice back in with fresh bedding etc.

To introduce new mice into a colony, you first need to sex them properly. Any mouse that is over 3 weeks can easily be sexed. Mice that are about a week old are also easy to sex. Females, when about a week old, just getting their fur growing in (the fuzzy state) have noticeable nipples. The males don't have these. At 3 weeks of age, testicles will start to drop in the males. Keep in mind that males of any age can draw their testicles back into their bodies, which makes them not as notiveable. (and yes exactly when you pick them up to sex them, just to be a pain LOL).

One way to tell a male from a female is the distance between the anus and urethra. It will be much greater in a male than in a female, pretty much twice the distance.

Ok, once you get them all properly sexed, this is the next step to introduce new mice into an existing colony. Take the mice out, wash the cage completely, add new bedding etc. Put in the male mouse and let him scent the place for a half our or so. Then put in the new females, let them get used to the male, then put in the old females. There will be some squabling as the females establish their pecking order but it shouldn't be as bad if you had put the females all in at the same time. Check them every day for any signs of stress, blood or mice cowering in a corner. If you do see one or two like this, remove them and house them in another container (if there is more than one, then just start a new colony or feed them off).

The best way to increase your breeding stock is to let some babies grow up and stay with their mothers. Of course you risk having some inbreeding but I find it is alot easier to switch in a new unrelated male into a group of females than the other way around (just clean the cage, put the male in first etc as explained above).

Never introduce new mice (male or female) into a colony that has babies. This will cause a major fight, and serious injuries on the intruder. This can also happen if the female is close to giving birth (up to about a week before). The females are highly territorial at this stage.

The adding of mice to an existing group is likely to lead to death in one form or another. The way that works best would be to take all the mice out and put them all together in a tub/bucket ...whatever. Clean the existing enclosure totally, fresh food, water and a new box if you use them. etc. Then dump them all in together. I have not had the kinder gentler mice described below. Mice are not socially accepting like rats.

Sounds like yours drove the new ones into isolation and either beat them to death or simple didn't let them eat or drink. I would toss them for sure as you don't know 'for sure' what or how they died.

You MUST know the sex of your mice. Mice DO NOT tolerate more than one male in a breeding group. (unless you have a half acre cage and loads of girls!...but realistically) Boys kill, castrate etc other boys.

If your group is producing then I would let them be. If you don't see bugs on the live mice you still might want to treat the bedding for fleas. Provided you aren't feeding anyone off in the near future.

If you want the group bigger you can raise a couple of the daughters up and let them start breeding in the group. Or you can try introducing girls as I outlined above.
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Sonya

Failure is not an option. It comes bundled with the software.