Rat Pup Cannibalism; Is it a good idea to mark pups?

My seven month old rat had a litter of ten yesterday. Today the litter is down to nine. There is food and water available and I am providing extra protein (cooked beef, eggs, etc.). My rat mom's littermate who is four months old was left in the cage with her per a university's advice. They stated the littermate would help mom, however, the littermate is always sleeping alone and doesn't go in the nestbox.

I plan on taking the littermate out and placing her cage beside mom's cage so they don't loose touch with one another. In addition I'd like to mark the pups with Crayola markers at the base of their tales with numbers. However, now I am hestitant to touch the litter since once pup has been consumed. In order to socialize pups they are supposed to be handled daily, but maybe socializing them at two weeks of age might be better in this case.

Mom comes to me and will run down my shirt like she always does to say hello. She doesn't mind me being near her litter and is not aggressive toward me or her littermate. I don't know what is going on. It could be that she is a first time mom. I don't know but do know I don't want any of her baby's to suffer by being consumed alive. Imagine the suffering they go through as well as the betrayal.

Hopefully most will make it to adulthood---but at this point it is unknown.

Hi fallblossom,
her cagemate should definitely be separated from the mom and litter. It's a stressfull time for all rats involved, and something as simple as a fight or stand-off could turn serious when it comes to a mother protecting her young. You handling the babies, however, will not cause the mother to attack or eat them-- that's actually a myth.

A lot could have happened to he missing pup. Possibly, there were only 9 to begin with; it's hard to count such small, squirmy beings. Another possibility is that it simply didn't survive due to natural causes, or died because of a defect, in which case the mother may have disposed of the body(a survival mechanism; not as traumatic to them as it seems to us). Generally, infanticide is extremely rare in rats, and will only occur if the mother is under extreme stress-- which it doesn't sound like she is.

Its not surprising to lose 1 or 2 from such a big litter for a young rat...this is actually pretty normal, and not mom canabalizing anyone. The baby died and mom cleaned up...its a natural instinct to get rid of a dead body that could draw attention from predators and also to get extra protein to feed the surviving pups.

Definitely move the cagemate out, but it sounds like you are doing just fine.

My rat mom is seven months old. Is this young?

Why does my mother rat start to go crazy rearranging her pups when I open up the shoe box to look at them? She frantically picks them up and moves them here and there and kicks the litter forward as if to cover them. Does this mean she is getting stressed from me looking at them? I've touched them in front of her and she doesn't bit, but she appears to act anxious. If she is then this means I probably shouldn't touch the litter---yet.

What about my daddy rat? Will he recognize the pups are 'his' when it's time to separate the males from the females? Should I be introducing dad to them or will he kill them because he doesn't recognize them as his (I would take mom out of the cage so he doesn't get her pregnant again).

Baby rats do not smell like rats so adults can mistake them for prey and kill them.
Don't put dad in with babies.
Adults can be introed gradually to babies when babies are 8 to 10 weeks old (10 weeks is better).

Yes mom is stressed.
Mom can take a break once in awhile from babies and visit with her friend and have out of cage time.
When babies are young, this would only be for a few minutes.
When mom is out of the cage, it would be a good time to check on the babies and handle them

I would recommend taking mom out of the cage for short play dates with her littermate, who should be in a separate cage by now. Once mom is out, that is a good time to handle the babies and check them over. When they are young, only do short times (ie 10 min). As they get older, the time can be increased a bit.
Do not intro the daddy to the babies. The boys will need to be separated from the family at 5-6 weeks. Let them get older, 10-12 weeks, before introducing them to their daddy. It is much safer that way.