Rat snakes are constrictors that eat rodents, birds, frogs, squirrels and bird eggs. They play an important role in many ecosystems by keeping the population of rodents at a constant, low level.
Rat snakes enter homes very often, as they are good climbers, and their prey is often close to residential areas. It is common belief that all rat snakes are non-venomous. However, according to the Savannah River Ecology Laboratory, recent studies show that some rat snakes, such as the Asian rat snake, are actually venomous. Even though some rat snakes may be slightly venomous, their venom does not really hurt humans. In most cases, rat snakes are not aggressive.