You’re probably familiar with honeybees and bumblebees. But did you know that there are over 20,000 species of bees, and most of them are solitary? In worker honeybees, certain brain areas grow larger as the insects get older and have more experiences. We wanted to know if this was also the case for solitary bees. We studied a particular type of solitary carpenter bee named Ceratina calcarata. We collected female bees of three different ages. Then we measured their brains and other body parts under a microscope. As expected, older female bees had smaller ovaries and more worn wings. But surprisingly, older bees had smaller brains than younger bees. We think that female C. calcarata bees invest their energy and resources into reproduction, rather than growing bigger brains.