She never tried this before but now that she's doing it often we are trying to get it covered up, we fixed a piece of fabric over it and used the wire from twist ties to secure it. I don't know why all of a sudden she's been looking for weird things to do in her tank, for a while she kept hiding IN her waterfall (going under the water and coming up into the hollow inside) so we had to cover the "pool" at the bottom. It's been almost a year since we cut that hole and she hasn't shown the least bit interest in it until recently. I think she's been subtly pushing it wider all this time so she can escape.

Just wanted to catch it on photo one time before we fixed it.