[Geordie]

Anyone know what could be causing this damage to my peppers 

Can't see any critters around or under the leaves.

[Headgardener22]

Little green caterpillars.

Some of them go back down into the soil in the daytime so they might be at the bottom of the plant, not on the leaves.

[Geordie]

Thanks Headgardener, inspected closely today and found a some very small green caterpillars which got squished.

Peppers have been sprayed - will check later in the week.