I've had a new betta for about 8 weeks now but in the last 2-3 weeks he has been sitting down the bottom of the tank hiding in the plants. Also the tank I have is a juwel reckord 60 with a boxed in filter/pump/heater in the back right corner. he tends to sit up there where the water gets sucked in and flattens himself against it... its like he's tickling himself or something! is this normal behavior?