Hot water tank nesting ground

We’ve avoided screens in the hot water tank intake or exhaust. There is a very strong, maybe guaranteed likelihood of some winter frosting causing the tank to stall. The opposite scenario has been less likely, which is some birds finding the intake and clogging it with plant debris to nest. The intake draw is even strong enough to suck it right into the blower motor at the tank. That can be a long way inside the house.