This article is from the Nov./Dec. 1995 AFRMA Rat & Mouse Tales news-magazine.

By Karen Robbins

Valerie Greco, Ontario, Canada
QDo male rats secrete a stronger scent when in the presence of females?

AWe’ve never heard of males secreting a stronger scent when in the presence of females. However, pheromones, which are a type of triggering chemical secreted by many mammals which alter or affect a recipient animal’s hormonal state, often trigger behavioral actions in surrounding animals and have a strong implication in controlling sexual behavior in mammals. Male mice will be stronger smelling after cleaning their cages to re-establish their scent in the cage. Cages, water bottles, etc., should always be washed thoroughly before using with new critters. Female mice have been studied and show strong affects that hormones have on the estrus cycle. Pheromones are also a part of communication. Animals housed alone are under more stress than those housed together or at least near enough to each other to communicate. With more stress, their immune systems are diminished and they may develop tumors and other problems sooner than animals housed together. See the M/A86:10, S/O86:11, and the M/J87:19 issues for more on pheromones.