If a hamster is feeling stressed, it may resort to cannibalism as a way to cope with the situation. This can be due to a number of factors, such as overcrowding, lack of food or water, or the introduction of a new hamster into the cage.
Lack of food or water
If a hamster is not getting enough to eat or drink, it may turn to cannibalism as a way to survive. This is especially common in overcrowded cages, where the hamsters may be competing for resources.
Introduction of a new hamster
The introduction of a new hamster into a cage can be a stressful experience for all the hamsters involved. In some cases, the stress may lead to cannibalism. This is most likely to happen if the new hamster is larger or more aggressive than the other hamsters in the cage.