It takes many of us a few hours in the morning—as well as a big dose of caffeine—before we earn the adjective “functional.” The humble cockroach, however, takes not being a morning person to a whole new level, and not just by not being people. What really sets them apart is the fact they’re literally unable to form new memories at the start of the day.Researchers tested this by attempting to teach roaches to like bad smells. Cockroaches normally dislike peppermint but are totally down with vanilla. A group of researchers trained cockroaches to prefer minty freshness by combining the scent with sugar water, performing this trick at different times of the day. What they found was that in the evening and overnight, the cockroaches were perfectly able to learn that vanilla had betrayed them and mint was awesome. When the same experiment was carried out in the morning, however, they continued to prefer vanilla.