Wondering if I should be worried about this! We bought our house two years ago, and each year around early July, we've suddenly gotten a swarm of bees outside the front third-floor window. They're big, we think they're carpenter bees but we're not certain. There's usually about 10-20 of them hanging around right outside the window, and a few dead ones on the outside sill, but none have ever gotten inside of the house so far. We think they are nesting under the eaves or in the woodwork under the window, but since it's on the third floor, we can't safely get up on the outside of the house to check for ourselves.

The first two years we had someone come and spray for carpenter bees which got rid of them, but it's expensive and they keep coming back each year. Now they're back again. Last year the exterminator said we don't really need to get rid of them since they'll go away on their own after a couple of months. Is this true? Can we safely ignore the bees, or will doing so lead to a bigger problem and damage the house? And if we need to get rid of them, is there anything we can do that will prevent them from coming back again each year? I live in southeastern Pennsylvania if that matters.