According to one study, macaroni cheese, scrambled eggs and boiled corn are among the favourite dishes of rats living in cities.
Rats don't have gall bladders or tonsils but do have a belly button.
Rats fit through extremely small holes – they have a 'foldable' skeleton: if the head fits through, the body fits.
In Gambia, giant hamster rats are being trained to track down landmines. They can smell the explosives and locate them, but because of their low body weight they do not trigger the mines.
Rats clean themselves more than six times a day.
Rats feel empathy.
Rats dream and process their experiences of the day.
The tails of numerous rats can tangle and knot together, a phenomenon called 'rat king'. Unfortunately, the animals die because they can't free themselves. The largest rat king consisted of 32 animals.
The rat's body hair stands on end; that may occur when the rat is cold or when stressed, such as during or after an intense altercation.