DEAR JOAN: I have been a gardener for many years now, and this is the first year I have seen this. My dwarf Meyer lemon tree, normally filled with lemons, has been attacked by what I think are rats. They have eaten all of the lemon rinds completely off and left the whole lemon, pith and all, totally intact. I have no lemons at all, however new ones are growing.

They have done this to my son’s lemon tree as well. He lives in Walnut Creek. His orange tree also has been attacked, however (the rats) have eaten their way through the rind, leaving a gaping hole, and completely eaten the inside of the orange.

I set rat traps, and for one week, the rats were gone. Then they returned. ARGGGG! Any suggestions?

— Judy, Sunnyvale

DEAR JUDY: While it might seem like the rats of suburbia have a personal vendetta against you and your son, it’s really nothing personal, unless your great-great-grandfather once wiped out King Rat in an epic rodent-human war. Probably not.

Eating lemon rinds and leaving the pulp, and eating oranges from the inside out are two classic rat behaviors. That you’ve never experienced it before is a sign that you’re lucky. Or you were. Now the rats know you exist and that you have fruit.

The most important thing to know is that rats have evolved to live alongside us, whether we want them to or not. They build their homes right next to ours — on top, below and inside our homes. It might seem like you’re experiencing a sudden influx of rodents, but the truth is the rats have always been there, just maybe not in your yard.

The best you can do is try to discourage them from visiting your yard, because visiting rats often become permanent residents.

Rat traps are effective in killing a single rat, but they don’t begin to deal with the overall population. That doesn’t mean you should switch to poisons — poisons kill more rats at a time, but they do so with great cruelty, and the poison is spread to unintended victims that eat the dying rat.

Exclusion is the best defense. First, look for places in your yard that might provide safe harbor for the rats. Ivy and ground covers are preferred nesting spots. Pull out the vegetative concealments, seal up openings under decks and into garages and attics and remove, at least temporarily, bird feeders that may be providing food for more than just birds. Take down bird baths and other sources of water. You want your yard to be unappealing to the rats.

If your lemon tree is small enough, you can try draping it in bird netting. Some people have good luck spraying their fruit with a hot pepper concoction. You can make your own or look for commercial brands. These work better against squirrels, but have been known to work on rats.

Rats breed at an alarming rate with a single female having up to seven litters of five to 12 pups each year. Rats reach sexual maturity at 3 months, so there seems to be a never ending supply. That’s good news for animals that have rats on their menu, but not so much for us.

Animal Life runs on Mondays. Reach Joan Morris at AskJoanMorris@gmail.com.