Halloween Lady Bug Party
I'm fairly certain they are the multicolored Asian lady beetle, or Halloween lady beetle, Harmonia axyridis. They were introduced in the U.S. in past decades to control pests such as aphids, and the websites I've read say they're doing a pretty good job. In fall they start to look for hiding places in which to overwinter. In some places they become so numerous they get into people's hair and fall into their food and drinks, although I think if one plunked into a martini it would suffer more than the martini.
Homeowners often express concern and aggravation with these nuisance pests. During late autumn, homeowners complain that multicolored Asian lady beetles cluster on the sides of houses; "crunch" under foot; get into food and drinks; alight on hands, arms, and other parts of the body; and sometimes enter the ears and mouth. The lady beetles can be so numerous that they appear to be "raining" outdoors or swarming like bees.
We first saw them in the mid 1990s. They show up every year on a warm, sunny day, always gathering in the same room -- the upstairs bathroom, where we live now, and on a west-facing, glass-enclosed porch in our old house. A few of them hang around through the winter; the others, I suppose, find a better place to hibernate than the bathroom.
We generally don't mind bugs coming into the house, although we don't go as far as some of insectophiles I've read about. William T. Davis, a pioneering entomologist who lived on Staten Island 100 years ago, used to keep a bowl of sugar water on his desk so bees would visit while he was working, and I think I've read that the writer Guy Davenport does something similar. We draw the line at mosquitoes and deer ticks, but the lady bugs are welcome. Our habits amount to a mutual agreement -- I have my drink downstairs, and they hold their lady bug party upstairs.