Signs of Hamster Pregnancy

Hamsters, like many other small mammals, breed quite often--and if you have a male and female hamster together in the same cage, chances are she'll get pregnant sooner rather than later. The gestation period of a hamster is about three or four weeks, although some Siberian varieties will give birth only 18 days after conception. Physical changes and changes in a hamster's habit are among the signs you can look for in a pregnant female.

  1. Hoarding and Nesting

    • The pregnant female will take up certain behavioral changes in preparation for the babies' arrival. You'll notice that she will begin hoarding food, keeping it stacked in the corner of the tank. She'll also begin building a nest in the cedar or pine using whatever bedding is in the tank. Do not interrupt these behaviors.

    Weight Gain

    • Rapid weight gain is one of the most obvious signs of a pregnant hamster. Over the course of her pregnancy, her appetite will increase, as well as her girth. You'll also notice that her water bottle or bowl will need filled more often; that's because she sometimes will be especially thirsty.

    Aggression

    • A pregnant hamster will display a noticeable increase in aggression toward not only any other hamsters in her cage, but you as well. She might be reluctant to let you handle her and even hiss and nip. She'll similarly protect her nesting area from other hamsters.

    Physical Changes

    • About a week before the babies arrive, you'll notice several bulges protruding from her abdomen. These are the babies, and you can view them by picking up the female and gently placing her on her back. You'll also notice that her nipples will begin to swell, becoming much more noticeable under her fur.