DEAR JOAN: I was wondering if you can help us figure what is eating our insulation. We have a window air conditioner, and we spray sealant in between the wood and the air conditioner. I hear scratching at night.

I have seen yellow jackets take the inside of the tree for their hives. I was wondering if it is something like that. We have checked for rat droppings and have seen none. We put out rat traps, but if it's rats, they go around them. I am wondering if it is a critter using the insulation to make nests.

I don't wish to put out sticky traps because the only thing I have gotten with those are birds and my dog who thought it smelled good or it was something new and interesting. Poor thing.

Could rats be the cause of the scratching noises heard by a home owner?
Could rats be the cause of the scratching noises heard by a home owner? ( Kimberly Jackson )

If you can give us a clue as to what it would be I would appreciate it.

Sherry

Bay Area

DEAR SHERRY: The most likely culprit is rats. Birds might take insulation for nest building, but we are past the time for that. Rats have a track record of getting into insulation, and just because you haven't seen evidence of them doesn't mean they aren't there.

I'm thinking perhaps they gained entrance through a space around the air conditioner, and they may be living in your walls. When you hear the scratching, try pounding on the wall near the air conditioner and then listen for sounds of scurrying.

There are very few nonlethal methods of dealing with rats. Peppermint oil is said to be a deterrent, and worth trying.

If you do feel forced to go the deadly route, please do not use poisons. As I've said more than once the poisons are cruel ways to administer death, and the dying rats can be eaten by other animals, passing the poison down the food chain.

Sticky traps are just as cruel. The rats struggle to get free, ripping off their skin in the process. Those that can't escape starve to death or die slowly from injuries incurred while trying to escape. As you experienced, they also can ensnare animals you don't want to catch.

The better mouse trap in this case is the old-fashioned mouse, or rat, trap. Rat traps aren't 100 percent effective and might not kill right away, so check them often so you don't leave an animal to suffer. You also can try an electronic rat zapper that electrocutes and kills the rat immediately.

Once you are rid of the rats, check carefully for holes and plug them to keep any more rats from coming in. That will keep the mayhem down to a minimum.

DEAR JOAN: Our lawn was graced with a large pile or two of long black feathers, at least two dozen, and some smaller fluff, where it looks like a crow met its match.

I saw no traces of a body, except what appeared to be a portion of a cleanly picked skull bone. I am sure this was not a cat who did this. Does it sound like a hawk?

Julie Machado

Hayward

DEAR JULIE: I wouldn't be so quick as to dismiss a cat. Although cats generally pick on smaller birds, a good mouser could take down a crow. However, I think a hawk is most likely the culprit as far as the killing goes.

A crow is no match for a red-tailed, Cooper's or sharp-shinned hawk, or a goshawk. They kill their prey by decapitating them and taking the body elsewhere to eat. Something obviously got to the head. That might have been any number of smaller creatures.

Contact Joan Morris at jmorris@bayareanewsgroup.com. Follow her at Twitter.com/AskJoanMorris.