Every October, what seems like a bazillion of them congregate on the south side of my house.
A few come in but they seem to be just stopping over for several days before going elsewhere.
It’s freaky.
I hate to tell you to beware because they probably are in your attic or siding during winter. Seems to happen most often in houses with cedar shake roofs or some easily available crevices. My sister has swarms of them every year and one fall I was staying in her upstairs bedroom with the window open, screen in and the uglies came in and covered the south wall inside. She vacuumed them up but I wasn’t convinced they were dead. It seems they have pheromes? that they leave behind to mark their place so they know where it’s safe. YUK
They moved on to our and our uncle’s place above Cumberland!