The rats here in Southern California are the same species of rat that carried the bubonic plague in Europe. They love the dead fronds hanging from the trunks of palm trees that provide a habitat similar to the thatched roofs of medieval European houses.
To anyone who is interested in learning more about these rats, take a look at this page. It illustrates the differences between Roof Rats and the more widespread Norway rats.
https://www.doyourownpestcontrol.com/roof_rats.htm
My workplace is now infested with mice and rats b/c a new boss decided to get rid of the feral cat population that lived under the buildings - and kept the rats away - they even gnaw through the sides of the buildings to get inside.
At home, I have a champion ratter kitty - she climbs into the fruit trees to get at the rats - she's cleared out our yard of these vermin - gophers too. I noticed an exterminator at my next door neighbor's house last week - he said he's got a rat infestation now, I think my atomic kitty drove the rats over to his property. I told him to get a cat...