yeah, i did much the same with a coke 2L bottle and a box as well with trigger door. everyfish and shrimp i had went in except my blue tang that i was trying to catch. they DO know. a stick is an interesting idea. i just put food and enticing treats and all were interested but the fish i wanted to catch, haha. had to take all the LR out and finally caught it.
i'll look for the thread a bit later, then. thanks!