severe mist
Sometimes, if you nuke player, it automatically triggers (land) attack to him
#Nuke = autoattack
slow niche
???
tender geode
Maybe you see this when you cut a part of their territory off with the nuke?
That part of land will then be automatically annexed by the biggest enemy neighbor. So maybe if you are that neighbor, you'll annex that piece of land (can be quite big) automatically after nuking them
I can't really see another reason for an automatic attack besides unknowingly pressing G for ground attack or something?