Pinworms
Sorry to change the subject so abruptly, but we got a notice from my kid's preschool that a case of pinworms has been confirmed in the student population. The notice includes symptoms to watch for, including increased itchiness at night since the worms crawl out at night to lay their eggs.

Question: How does a pinworm know when it's night, 'specially when it spends most of its time where the sun don't shine? - served up by Ralphie @ 11:12 AM