Question
Our question is, how many rats can live on or near a normal sized city lot?

After living in San Antonio for two years and putting out bird food during that time, we started seeing rats eating the food in the daytime.  They must have always been there but we weren't aware of them until seeing them.  Our lot has many trees and bushes, several decks, a greenhouse, and a shed so there are many places for them to run underneath.  Our attic has traces of their being up there, but traps didn't catch any.  We quit putting out bird seed and began taking the suet and compressed corn in at night.  I think we finally devised a way to feed the birds on a tall pole where the rats can't get to it.  We continue to set traps and keep killing rats inside the greenhouse.  Our American Eskimo dog has killed 3 rats but we make sure he will not be harmed by a trap.  How can we get rid of the rats?   

Thank you.

Answer
I really don't know much about rats other than they can easily be caught in live cage traps baited with apple slices or peanut butter. Cats work as well. I make electronic deterrents but rats are in a class by themselves and I've not come up with an effective control. Even if I had one, just chasing them off to breed nearby isn't a good solution.

Rats are a pest in many ways. One of the worst is chewing wiring in two which can mess up vehicles real bad or burn down your house. Rodent caused fires or damage are not usually covered by insurance!