@EdgeOErin If you mean macro-creatures (I would run or seek protection from lots of micro-organisms!) I suppose anything fast that can pump venom into me and be dangerous.
Ants, definitely. I've sought cover or protection or distance from tiny ants.
I got stung by a bullet ant once. Shit, I will hang from a chandelier to not get one of those on me. Ouch!
@EdgeOErin The venom apparently cranks your nerves up to the maximum pain setting. I'd compare it to a cluster headache or to having molten iron pounded into you, except it is one long unending pound, because there's no room for up and down in maximum ouch.
People have described it as being like being shot, hence the name.
I either haven't been shot, or didn't feel it when it happened, so I don't know, but I doubt being shot really compares, it'd just be the next worst thing someone thinks of.