There are two possibilities that come to mind: earwigs (not my first choice) and slugs or snails (most likely in my opinion). Earwigs are basically ground walkers. They do crqwl up stalks of plants, but they're not notably a pest of strong smelling plants. The slope outward of the clay pot may not have been too appealing to them, ei

I.m not sure what happened here. I thought I had sent you a full answer, but my computer doesn't think so. I mentioned that earwigs can be held off by dampening a roll of newspaper and laying it on the ground at night next to the plant. In the morning, do not open the paper, but transfer it to a plastic bag and dump it in the trash. If your chewer is a gastropod (slug or snail) it should leave a slime trail up the side of the pot. There are all kinds of poisons you can use to thwart slugs and snails, which will not harm your plants, but will kill or discourage the culprits. Good luck.

Thank you so much !

You are very welcome. Hope your basil survives.

You are welcome. Didn't know that earwigs or their other gluttons liked basil. I do! marjorie.