I've posted this story before, but could not locate it on an archive search, so I'll retell it-
We had a calico named Yankee who loved knocking over water glasses, too. One morning when my son was getting ready for school she was in the bathroom with him, but she kept trying to knock over his toothbrushing rinse water, so he impatiently put her on the toilet to get her out of his way. He laughed when he noticed she then proceeded to attempt to knock over the toilet!