oh, my little guy loves to try pushing at his screen top, it is an exo terra tank so the clip locks are really secure. I use the front door opening to do maintenance, The front doors swing open and i have a double lock on the front. He learned real fast where the door is, cause when i am done with spot cleaning and water, he is right there looking to try his luck. I also use this opening to take him out to handle, and he seems to learn fast.