Have no idea, but the DR. Optimara site offers one possibility (flea beetles)

http://www.optimara.com/doctoroptimara/diagnosis/fleabeetles.html

I just tried Googling your description.. There are some serious experts on this site. Hope one sees your post.

These beetles - whatever they are - if you make a pic - probably somebody will come with the name - are not AV specific - and we do not see them in the collections. probably something that came from outside or with the soil. Do they damage the leaves?

If you do not want these passengers - you can get something not very toxic from the store - like 3-in-1 spray based on neem oil - and spray the surface of the soil several times until they disappear.

I.