I occasionally crave pencil erasers. This began with my first pregnancy and has continued for the past 15 years. I don t crave them every day, and will sometimes go months without even thinking about one, then all of a sudden I have a huge craving. Similarly, if I inhale (as in one deep breath, not continuous) rubbing alcohol or suck on shaved ice, that will decrease the cravings. My question is: what can cause this and are there any actual side effects?