just a little update on my octo whom ive decided to call "conan the destroyer" since all it seems to do is destroy all my fish... went in last night and watched it stalking my cardinal fish which it will probably never catch. seems to be fine. all night its crawling around the rockwork in the tank looking for food and during the day it spends its time sitting just out of view watching the world go by. ive only been feeding it during the day to try and encourage the daytime behavior and it slowly seems to be helping. just out of curiosity though.

has anyone ever had an octopus that doesnt ever find one particular den but instead just ends up where ever it finds a comfy spot at the end of the night? mine has only stayed in one den for 2 nights at most then it just finds another one. i dont know if its due to the fact that literally half of my tank is live rock and it just feels safe everywhere or if its just the species i have since it is somewhat of a tidepool species. anyway just curious because none of the previous octopus ive owned have ever done this.

Joe,
Since a lot of the behavior for the little Mercs does not translate up to the larger octos, I don't know that my observation helps but neither Trapper nor my 4 males kept (keep) a den for more than a couple of days. Dens are revisited and trapper seemed to make a regular circuit (counter clockwise) of the tank until she started brooding. Miss Broody, however, chose a den after being released to the tank and never slept anywhere else (until her disappearance 4 weeks ago) even before she mated.

My hummelincki (definitely diurnal - only with us 1 week so far) found a den her first night and returns to it nightly or when she wants me to "go away" difference is she will go in with no one present and not come out until the next day at bed time but the "go away" escape is only temporary and she will come out again when we leave the tank front).

Olorin has 3 or 4 "dens" that he bounces back and forth too.While Achilles has a few resting spots but only one I would call a den.