What happens if two hamsters share a cage?

Two hamsters in one cage usually bite and fight each other, because hamsters are solitary animals with very strong territorial instincts. Shared caging leads to fights over territory, causing hair loss, skin injuries, lost ears or limbs, and even death.

If a male and female are caged together during the female’s heat, the fighting may be milder and they may mate after some contact, but they will fight again once mating is done.