I was recently told about a woman who cut her tongue licking an envelope. It didn't heal properly and her tongue began to swell. She went to the doctor and was given medicine to reduce the swelling, but it didn't help. It finally swelled so much she had difficulty speaking. She went back to the doctor and he decided to cut open her tongue. It turned out the swelling was caused by some cockroach eggs, which had apparetnly been on the envelope, a few of which had prematurely hatched.

I know that sounds like an urban legend. I have no idea whether it's possible or true. I just thought I would share.