I guess is must be hot. I've had to fill the water feeders for my ants after just 3 days and normally it lasts them a week. They are getting better about getting off of the feeder when I need to remove it. (I can't refill it if it's covered in ants and there is no way to explain this to them. So I just tap it to scare them off.)
I think I'll need to give them each two water feeders just to be safe. (No water harms ants faster than anything. They could last a week maybe two without food.)