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?

A: 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.