Hamsters may attack or even "eat" other hamsters under specific circumstances—though this behavior usually involves fatal biting rather than actual consumption of the body. It is not a common occurrence and primarily depends on factors like species, gender, environment, individual temperament, and resource competition. Below is a detailed analysis:
1. Triggers for Hamster Aggression Toward Conspecifics
Species Differences
Campbell’s & Winter White Dwarf Hamsters (e.g., "Pudding" and "Silver Fox" morphs): These are highly solitary with strong territorial instincts. When housed together as adults, they easily engage in fierce fights over territory, food, or mates—often resulting in the death of one or more individuals.
Roborovski Hamsters: Generally milder in temperament, but adult Roborovskis may still attack peers due to stress or limited resources. Fatalities from such attacks, however, are relatively low.
Syrian Hamsters (e.g., "Golden Bears"): Larger in size and highly territorial. Housing adult Syrians together carries extreme risk, as they may kill each other outright.
Gender & Age Factors
Same-Gender Housing: Adult hamsters of the same gender—especially males—are the most aggressive due to territorial competition. They can barely coexist long-term.
Opposite-Gender Housing: Males may attack females when the latter are not in heat. While they can live together briefly during the mating period, the male must be separated immediately after breeding. Otherwise, he may harm the female or her offspring.
Juvenile Stage: Hamster pups can be housed in groups temporarily before 4 weeks of age. After weaning, they must be separated into individual cages to prevent fights over food.
Environmental & Resource Limitations
Insufficient Space: A too-small cage restricts hamsters’ movement, increasing the frequency of conflicts.
Scarce Resources: When food, water, or hiding spots are inadequate, hamsters will fight to claim these essential resources.
Unfamiliar Scents: Introducing a new hamster or exposing existing hamsters to foreign scents can trigger territorial instincts, leading to aggressive behavior.
2. The True Nature of Hamsters’ "Cannibalistic" Behavior
Not Actual Cannibalism
Hamsters’ so-called "cannibalistic" behavior typically involves fatal biting, not eating their own kind. Aggressors may attack due to territoriality, stress, or misjudgment—but they rarely consume the body of the deceased hamster.
Exceptions in Extreme Situations
Severe Starvation: If hamsters are deprived of food for an extended period, they may attack weaker conspecifics out of survival instinct. This scenario, however, is extremely rare.
Maternal Protection: After giving birth, mother hamsters may attack other hamsters (including males) that approach their pups. This behavior is for protecting the litter, not for consuming the intruder.
3. Preventive Measures Against Hamster Aggression
Housing Hamsters Separately
One Hamster per Cage: Adult hamsters must be housed individually. This is the most effective way to avoid inter-hamster fights.
Breeding Separation: If breeding is planned, remove the male hamster immediately after mating to prevent him from attacking the female or her pups.
Providing Sufficient Resources
Adequate Space: The cage area should be at least 5 times the size of the hamster’s body (e.g., a 47-liter basic cage is suitable for one hamster).
Plentiful Food & Water: Place multiple food bowls and water bottles in different areas of the cage to avoid competition.
Adequate Hiding Spots: Provide tunnels, wooden huts, or other hiding places to reduce direct encounters between hamsters.
Minimizing Stressors
Avoid Frequent Disturbances: Reduce unnecessary cage changes, cleanings, or handling to minimize stress for hamsters.
Quarantine New Hamsters: Isolate new hamsters in a separate cage for 1–2 weeks to monitor their health. Gradually introduce their scent to existing hamsters (if cohabitation is attempted later) to reduce territorial reactions.
4. Observation & Intervention
Signs of Impending Fights
Frequent chasing, squeaking, raised fur, and bites (especially on the ears or tail) are early signs of conflict. If you notice hamsters pinning each other down, drawing blood, or hiding and refusing to eat, separate them immediately.
Treating Injuries
Minor Bites: Clean the wound with physiological saline and apply a pet-specific disinfectant (e.g., povidone-iodine).
Severe Bites: Seek veterinary care promptly, as the injury may require stitching or antibiotic treatment.