1. False Pregnancy:
* This is the most likely scenario. Female hamsters can exhibit many signs of pregnancy even without being pregnant. This is called pseudopregnancy and is caused by hormonal fluctuations.
* Signs of pseudopregnancy: Nesting, weight gain, enlarged nipples, aggressive behavior, and even milk production.
* It's important to note: Pseudopregnancy can be dangerous for female hamsters. If it persists, they can become aggressive, depressed, and develop health problems.
2. Previous Mating:
* It's possible your female hamster was accidentally exposed to a male hamster at some point in the past, even if you haven't seen it happen.
* This could have occurred during a brief period of time when they were housed together, or if they shared a common area.
* Important: Even a single mating can result in a successful pregnancy.
3. Misinterpretation:
* It's also possible you are misinterpreting the signs of pregnancy. Some common behaviors and physical changes in hamsters can be confused with pregnancy.
* For example: Weight gain can be due to overfeeding, and nesting behavior can be triggered by other factors like stress or boredom.
What to do:
* Observe your hamster closely: Pay attention to her behavior, weight changes, and any other unusual symptoms.
* Consult a veterinarian: A veterinarian can examine your hamster and determine if she is truly pregnant or if there's another underlying issue.
* Separate your hamsters: If you have a male hamster, it's crucial to keep them completely separated to prevent accidental breeding.
It's crucial to take your hamster to the vet to determine the cause of her symptoms and to receive proper care.