Wow! What a determined little hammy. I haven't had to worry about my dwarfs, Toffee & Almond getting at the hole in their cage. I crazy glued a plastic round from the center of my patio table (it usually covers the hole where the umbrella goes
) to the opening for the water bottle. It seems to have solved the problem. I have a Tamburino Naturala. Almond was the one who noticed the opening, but couldn't reach it. Toffee is bigger so I figured...let's nip this in the bud. So far, so good. Hope you get Fred to behave