ladybugs when I had an organic garden in the San Francisco bay area. I learned ladybugs are beneficial and eat aphids. Back then in the Spring I actually purchased ladybugs to release in my garden. A ladybug can eat up to 5,000 aphids in it's lifetime.
A few years later I moved to the Sierra Nevada mountains. One year in the late fall I discovered millions of ladybugs congregating at the base of an old stump clumped together. I learned they were gathering together to hibernate for the winter.
Recently here in the Georgia mountains I've found a few ladybugs in the house up in the corners of an upper bedroom. The ladybugs won't do any harm and will leave in the Spring.