If there are no slime trails it can be earwigs or caterpillars. Spray with BT, and if the problem does not end I'd suspect earwigs.
Renee

Earwigs will eat the plant?

Oh yes. The plant, the flowers, the fruit...
I didn't realize this until last year, when I got an earwig population explosion. I had no idea what was eating my brugmansias until I went out at night with a flashlight- HUNDREDS of earwigs chowing down.
Renee

Thank you all for your advice! We are going to try going after the slugs first. If that doesnt work we will move on to spraying with the BT (which is a little more expensive then the slug stuff). Hopefully we can get this licked because we really like growing things. It is a bummer to see our plants getting killed!

The edges of the missing tissue look to be "sealed" so I suspect the damage is rather old. May have occurred when the leaves were very small. Little holes at that stage become big holes during normal leaf expansion.

That said, I would still go out at night, 10 PM or so, with a flashlight & look, especially on the undersides of the leaves. If the critters are still active, you'll find them and can dispatch them on sight!

BTW, earwigs make small raggedy holes, not tidy ones as are in your leaves.

Slugs and snails love peppers. I keep a pepper plant in my orchid house as a "magnet plant" so that I can go out at night and remove any slugs that I find there.
But really, your pepper in your photo looks quite good. You're not going to have pristine foliage and it isn't necessary. Sometimes the predation is so heavy that the leaves are almost skeletonized and the plants photosynthetic ability is diminished. Then you've got problems. You might also have leaf-cutting bees. They leave holes but it's not typically catastrophic damage.

I get that same stuff on my basil, mint, and peppers. The really cool thing is, they do NOT touch the peppers!! Could be leaf hoppers, thrips, leaf miners, spider mites, and all kinds of evil bugs!! Snails and slugs don't live here. It's too hot!

I blast the leaves with water to get the spider mites off, and spray with soap and water now and then, but I also spray with insecticide.

Just wash it off really good!

Suzi

I found the exact same holes as yours in my basil, then witnessed a white fluffy caterpiller munching along. I should have taken a picture, but I was so mad I threw it over the fence! (First timer) The irregular holes in my bell pepper looks like the same as the ones made by ants on my tomatoes.