My frog is being weird

[DG Kim]

So I've had my Fantasy Pacman frog, Cheeseburger, since November 2015 and he's been doing good so far. Eating, pooping, growing, everything seems to be fine and I've been keeping the enclosure at the recommended temperatures and humidity. I have him in a 10 gallon tank with live plants and have been spot cleaning regularly and cleaning the tank once a month, though I started doing every two weeks since I moved the plants into pots.

So anyways, the past couple of weeks I've been hearing a thumping noise coming from the tank but didn't think much of it and when I would go to check, my frog would just be staring out into the distance. Last night i finally caught him making the thumping noises, and it turns out he's been trying to climb out of the tank! I was able to observe him in the darkness for a good 10 minutes (no video footage because it was too dark) and during that time he was moving all over the place, going from one end to the other seemingly looking for a way out. It looked like one of those horror films where a person is trapped in a room and banging on the walls crying for help. This seems to happen usually after I feed him since that is when he is most active. In addition, nowadays he seems to spend a lot of time at the front of the tank staring out into the distance, watching me sleep (my bed is right across from the enclosure).

Any experts here have any idea why he might be trying to get out? I don't think he's looking for more space, but I do have an empty 18x18x18 if he needs more in the future.