The kind of rats we have here are called brown rats, which is a really boring name, but it pretty much describes them. Sometimes they are called Norway rats, sewer rats, Hanover rats, or wharf rats. The fancy scientific name for these rats is Rattus norvegicus, which means "Norway rat." And the reason the rats got this name was because the scientist who gave them their name thought the rats had come to England on ships from Norway in 1728. But he was wrong about this, because guess what, there weren't even any rats living in Norway yet in 1728.
|The rat hole in Henry's yard|
Our rats like to live in the sewer, which is a big pipe that runs through the ground under the street. Rats are good swimmers, so they don't mind if the sewer is full of water. A lot of the time, the rats just go in the sewer through the drains because that is less work than digging a tunnel. But sometimes they dig a hole, and we can see these holes when we are out walking with Mom. There's a rat hole in Henry's yard, and Henry's dad keeps filling it up, but then the rats dig the hole out again.
A female rat can have three to five litters in one year, which is a lot of baby rats. Some rats live to be three years old, but 95% do not even make it to their first birthday. This is because there are a ton of predators out there eating rats. If a whole bunch of one group of rats dies, the ones that are left start making lots more babies to get the number in their group up again.
Brown rats can carry a bunch of nasty-sounding diseases with names that are really hard to spell, so I am not going to tell you what they are. Some people blame brown rats for the bubonic plague, but actually it is the fleas that bite black rats and some other rodents that made people get sick from the plague. After there started being lots more brown rats than black rats, there stopped being so much plague.