Just dug up a few pototo plants and I noticed that, there were one or two black beetles in the soil.
They haven't harmed the crop but I was just curious what they were doing there?
Are they a threat?
They are most likely to be ground beetles of some kind. There are lots of different types but they are all friends. They eat other insects, slugs and dead bodies of small animals. Probably keeping your pots nice and tidy.