really, you should have stayed back and let nature take its course. too many humans think they "know" whats best for critters but end up making things worse. its hard for many people to stand back and let things happen. just because animals were bought from a shop doesnt mean they lose their instincts. every animals brain is programmed to do certain things.

with any animal, some mothers will kill their babies either due to malnutrition or because they know they cant handle it while others are accidental. humans have this problem with thinking they know whats best for animals when they really have no clue.

i say you made a big mistake removing the babies. many animals will kill their first litter but turn out to be great mothers next time around.

that said, i have been breeding dwarf hamsters and mice for a couple months, and my rats just had their first litters with another due today or tomorrow. 10+ hamsters litters, 6+ mice, and now 2 rat litters so far. 1.5 litters of hamsters and 1 litter of mice died after i thought i was helping. the ones that i didnt even touch until their eyes were open all survived...

rats in captivity and the wild will bury their babies to keep them warm when they are out feeding. with no fur or fat on the babies its hard for them to stay warm and the mothers know this so they give them a "blanket" to keep warm.