Did you check the pictures I linked? Does that look like the damage? Ants like sweets. They typically eat fruit. Strawberries in particular. They do appear en masse on plants that have aphids. They have a symbiotic relationship. The ants protect the aphids, and the aphids secret a sugary substance that the ants harvest.
You might have aphids, but they wouldn't do the damage that you mentioned. If you think ants are your problem, a product named Terro works like magic. Very inexpensive. It's boric acid in corn syrup. They take it home, and it destroys the entire nest within days. Not gonna say that it 'can't' be ants on your cabbage, I've just never seen it. I grow broccoli, not cabbage. Stranger things can happen.
You didn't find green caterpillars?
Terro
https://www.walmart.com/ip/TERRO-Liq...RoChRcQAvD_BwE