I have a screened in porch with holes in the screens. What kind of bug eats holes in screens?

The damage to your screens are probably caused either birds, squirrels, rats, or some other small animal that is either tearing the screen while crawling up it or flying into it. Since the damage is limited to the top areas only, my guess would be birds. They will claw and peck at screens when they are trying to find little nooks and crannies to nest in. Tears will happen quite easily when the screen is thin, cheap 'fabric' type screen or older screen that is either dry rotted, rusted out or otherwise easily damaged.

The four legged meowing variety can cause holes in screens if they are a young cat who likes to run up them and hang. Do u have a cat? Inside only cats are the worst at this. Acid rain? Cleaning chemicals for glass? Projectiles, do you ever find stones or small beads or pellets inside the house, could someone be throwing stones at the window, or using a bb gun nearby. ie kids in neighbouring yards. Is there a tree or bush growing outside that sways in the wind and touches the screen. Birds or frogs, sometimes in certain conditions insects gather on the outside of the screen this can attrach frogs and lizards/geckos or even bats. All three attract birds who might put a hole in the flyscreen with their beak if they are a bit aggressive catching their prey. Also it could be frog pee, I have heard its quite acidic. Also sometimes birds can fly into windows if they are very clean and reflective the birds might not see the window properly fly into it beak first. Ok thats all I can guess without knowing the weather or animals where you live. Love and Light - Alison

It may be cockroaches they will eat through most things, are the screens fibreglass?Try spraying antiseptic on the screens here in Australia we have a product called detol, if you mix this with water into a mild solution and spray it on the srceen this may repell the particular incect thats munching your screens

I wonder if some kind of moth would be doing that. I know what you're talking about... I've had the same thing. I can't tell you if it is a bug or maybe a woodland creature, but I have solved it by getting metal screens.