My octopus Proteus stopped eating and coming out to hunt about three weeks ago, so I assumed he was getting old, since I read that octos often stop accepting food once they're near death. He's a pretty tiny octopus (mantle length less than one inch) and he's at least 6 months old now, so that seemed a reasonable lifespan for an octopus that size. I tried putting a snail right next to Proteus's den and he actually grabbed the snail and shoved it away! However, yesterday I saw him try to grab at a shrimp that just happened to flit near the den, so I bought some hermit crabs today and he perked up right away when he saw them and ate those right up. He still doesn't seem to want to come out to hunt though. He wouldn't come out for the hermit crab. He just reached out and grabbed it when it got close enough. What do you guys think is going on here? As far as I know there were no changes in water quality during this time; I check the water regularly and I didn't see anything odd. I feel pretty bad about keeping him hungry these past three weeks now! I assumed if he was hungry he'd come out and grab one of the shrimp. I don't know why he rejected that snail earlier. Maybe he thought it looked too big to eat.