do they hide alot, are they nocturnal?

thanks all, that's a good idea. unfortunatly, any zuchninni I put in the tank would be immediatly gobbled up by the bala sharks. They LOVE it. that's a dilema that I haven't figured out the answer to yet. How to feed the BN pleco's zuchninni without the sharks getting to it first and eating it.
 
Perhaps its worth trying to hide it in the planted areas?

And i agree with the majority of the comments above, Generally quite a shy fish. When i bought mine they were on the glass day and night, fightign over territory with my betta. Then they went through a phase of hiding in the little driftwood cave, literally reversing into holes they shouldn'ta been in. lol
And now..they are about...3'' and are back to going where ever they please. Quite active during the day, not sure about the night. The male is constantly chasing the suspected female.
 
AquariaCentral.com