Rats are various medium-sized, long-tailed rodents. They are typically distinguished from mice by their size. The main types we deal with in Texas are the Roof rat and the Norway rat, although there are other species.
The roof rat is normally found along coastal areas, and they feed mostly on vegetation and fruits. The local Norway rat eats meat, dog food and tends to like greasy foods.
Rats are instinctively wary of things new to their environment and very aware of their surroundings. They can enter a home or building through a hole the size of a quarter. (Mice can enter through holes the size of a dime.) They are dangerous living companions due the fact that they are unclean and carry many infectious diseases, and they can introduce disease-carrying parasites into your home.
image from icwdm.org/handbook/rodents