I had a millipede infestation at one point too, although they are harmless to mature plants, I noticed that I wasn’t able to germinate any seeds when they were around. I believe they eat sensitive seedlings (though maybe larger seedlings will be ok)
Hmm, yeah they do chomp on those too, since seedling is softened it’vs easier to be eaten. But i usually just germinate in the tray before transplant so i didn’t have this problem.
On the bright side, they might be helping you get rid of unwanted weed before they germinate.