hi...i'm a new member! right now i'm in South Caicos (Caribbean) taking a marine ecology class. for the past few weeks i've been checking up on a caribbean reef octopus that lives near the school's dock. i had only seen him inside his den up until last night when i finally saw him half out of it. unfortunately, my dive light scared him back inside, but as i watched, i realized he wasn't the only guy in the neighborhood. at least 20 hermit crabs were crawling in and around his den, at one point even completely blocking the entrance for a good 20 minutes. i have never seen so many crabs at once before, much less around a predator's den! i assume they were there scavenging empty shells from the octo's latest meal (of which there are always many scattered about), but still i was surprised--i have never heard of anything like it! can anyone shed some light on this? thanks!