Our pool is within a large fenced yard which is easily accessed by the many squirrels, chipmunks, and mice living in the area. Finding dead mice in the filter basket is a pretty regular occurrence that has never bothered me much, but I am a little bothered by the chipmunks -- I suppose because they are cuter and friendlier.
I've always presumed part of the issue was the suction of the filter. However, I was away over the weekend, leaving the pump off, and came home to find three baby chipmunks floating around. This seems odd to me since the normal water level is within a centimeter of a large set of steps at one end which I would have thought such an animal smart and agile enough to use to escape.
This is obviously not the case though, even with the adult squirrels. Several weeks ago I saw one swimming frantically around and watched it for a while to see how long it took to find the steps. It did, but it did not make any attempt and then avoided the low step in favor of trying to claw its way up the vertical sides -- which was impossible; eventually I had to rescue it with a net.
They aren't doing any damage, but I am now contemplating ways to build a low angle, rough wood surface ramp that can be left somewhere in hopes their little brains and claws will latch on. My guess about the step is that squirrels are not fond of swimming and panic prevented it from trying anything besides paddling and trying to go up a vertical.
Has anyone here done anything like this successfully? I realize a hardtop cover such as people use to prevent the same problem with large pets would work, but this would be a bit of a hassle since I do not want to be taking it on and off all the time and rodents like this probably only last a number of minutes in the water before they exhaust themselves.