Plus some ants, wood ants I think, spray formic acid
Anting is only done for the formic acid. I have observed a tame pet crow do anting. They don't need an ant nest to do it, just a lot of ants running about. As well as spreading out to allow the ants to crawl all over them, they also pick up ants with their beaks, which as a result of squeezing them releases large quantities of formic acid. The other ants crawling over the bird are actually attacking it and are therefore spraying formic acid. The ants do not attempt to remove parasites. I've heard it suggested that corvids can get excited by the such things as a slice of lemon, as they confuse it with formic acid, although I've never tried it. And yes, anting is pretty orgasmic for corvids, and quite amusing to watch.