Backglass wrote:Check your liner for holes. If you have a very large ant colony behind you liner, they could be "falling in" through the cuts/cracks.
If you don't have a liner, do you see these ant anywhere else? On the deck or in the trees nearby? Follow them home!
I agree with this as well, Check your liner for sure,
They are usually found behind the liner, A lot of times the ants like to eat the vinyl , I used to see this a lot when I pulled peoples winter covers out of the shed after a long summer,
You might want to call an exterminator as well, about the problem