They do release formic acid which smells rank. But I’ve only ever smelled it from a large pile of dead ants. Not a few walking around outside or in a house.

Huh didn’t know other people couldn’t smell ants but for me I find i have to get close and sniff them to get a cent I also get the same cent from dead spiders and I wouldn’t call it offensive but it is quite distinct so it gets a huh out of me every time I catch the cent