Sometimes I hallucinate cats, or other small animals like squirrels. I see them from the corner of my eye, and then when I go to look at them, they aren't ther

Sometimes I hallucinate cats, or other small animals like squirrels. I see them from the corner of my eye, and then when I go to look at them, they aren't there. They usually show up when I'm under stress. I kind of like them, because they remind me to try and relax a bit more.