No offense to any woman out there, but she may be going through her breeding cycle, much like women go through ther periods, or she may be going through the hamster equivalent of menopause...
Hamsters are territorial by nature and she may just be getting territorial...
Hamsters are generally solitary and primarily nocturnal though also can be considered crepuscular as they are sometimes active in the early morning or late evening. They are excellent diggers, constructing burrows with one or more entrances and with galleries that are connected to chambers for nesting, food storage, and other activities. They also like appropriate tunnels made by other mammals; the striped hairy-footed hamster (Phodopus sungorus), for instance, uses paths and burrows of the pika. None hibernate during winter, but some experience periods of torpor lasting from a few days to several weeks. Hamsters are known to stockpile large amounts of food. Hamsters dislike swimming but if forced to will inflate their cheek pouches with air to help them float.
Hamsters become fertile at different ages dependent on their species, but this can be from one month to three months of age. Male hamsters remain fertile for the rest of their lives, though females do not. Females are in heat approximately every four days.
Breeding season is from April to October, with two to five litters of 1 to 13 young being born after a gestation period of 16 to 22 days. Gestation lasts 16 to 18 days for Syrian hamsters, 18 to 21 days for the Russian hamsters, 21 to 23 days for Chinese hamsters and 23 to 30 for Roborovski Hamsters. The average litter for Syrians is about 7, but can be as great as 24, which is the maximum number of pups that can be contained in the uterus. Campbell's Dwarf Hamsters tend to have 4 to 8 in a litter but can have up to 14. Winter White Russian Dwarf Hamsters tend to have slightly smaller litters, as do Chinese and Roborovski hamsters.
Hamsters are born hairless and blind in a nest which the mother will have prepared in advance. She uses shredded material such as leaves in the wild but prefers cotton or toilet paper in captivity. After one week they begin to explore outside the nest. They are completely weaned after three weeks, or four for Roborovski Hamsters. Most breeders will sell the hamsters to shops when the hamsters are anywhere from two to eight months old.