Question: We had our ceiling sprayed more than a year ago and about two weeks later, we began seeing worms, like maggots, on our ceiling.

I'm sure there were some kind of eggs in the plaster, and they just began hatching. We've been vacuuming them off, but every morning and throughout the day, there are more. I don't know what to use to kill them. Can you help?

Answer: What you are seeing is most likely Indianmeal moth larvae, said Jeff Hahn, an entomologist with the University of Minnesota Extension. They feed on a wide variety of dried food products, such as pasta, flour, whole-grain foods, nuts, spices, pet food and birdseed.

So what are they doing on your ceiling?

When they are full grown, they commonly move away from a food source and look for a place to pupate. That's when people typically find them on walls and ceilings. They did not lay eggs in the plaster of the ceiling, but instead came from a nearby food source.

Treating the ceiling does not control the problem. Instead, find the source of the infestation (their food supply) and eliminate it.