Hamsters do not have menstrual cycles—this is one of the physiological differences between rodents and humans. Below is a detailed explanation:
I. Characteristics of Hamsters’ Reproductive Systems
No Menstruation
Hamsters belong to the order Rodentia, and their reproductive systems differ from those of humans—they do not shed their endometrium periodically.
The only rodent confirmed to have menstrual cycles is the African spiny mouse, and hamsters are not part of this group.
Estrus (Heat) Symptoms
When female hamsters are in estrus (once every 4–5 days), they may secrete white mucus, act restlessly, or make vocalizations, but there is no bleeding.
II. Possible Causes of "Blood Stains"
Food or Urine Discoloration
Red-colored urine may be caused by eating pigment-rich foods such as beets or carrots.
Health Issues
Blood in urine: May indicate a urinary tract infection or kidney stones.
Genital bleeding: Could result from mating injuries, uterine infections, or tumors.
External injuries: Scratches from sharp objects in the cage or fights with other hamsters.
Other Cases
A small amount of bleeding during labor is normal, but heavy bleeding after delivery requires immediate attention.
III. Precautions
Seek veterinary care for abnormal bleeding: If continuous blood stains are found, contact a veterinarian immediately to rule out diseases.
Avoid misjudgment: Do not confuse estrus behaviors (such as lifting the hindquarters) or urine discoloration with menstruation.