I actually like the defense smell of Carabus species - the scent is pungent when too close, but from a certain distance, at least to me it is a very pleasant and interesting smell - a sweet-spicy something. I have also been wondering for some time whether similiar looking species of that genus can actually be distinguished by their smell; maybe to be used in the next field guide :-D
Also, ants: The Citronella ant from the genus Lasius isn’t named for no reason, and during a scientific talk from a myrmecologist (which took place on the last possible day before the public shutdown) I had an ant trail - as fate would have it - going right under my chair. Mentioned it to the speaker and he took one ant between two fingers, smelled it, and had it identified as Lasius emarginatus. Doing the same, I certainly could sense a certain odor, but would not dare to use it as a defining feature for species ID.
We’re now slightly getting side-tracked by switching sensory perception, but the heck, tasting is almost smelling and I like the story:
The very same person also had a scientific essay published last year, where he reflected upon the similarities of two - unrelated - ant species, and whether it might be some sort of mimikry. So he did a science and put himself into the role of an ant predator: helping himself with some individuals of each species, only one had a deterring taste - so he concluded a form of Batesian mimikry developed by the tasteless species.
Recalling his remarks upon my first encounter with the allegedly bad-tasting species - curious as I am - I wanted to confirm his experience and decided for some entomophagy (not before having it iNatted, of course!).
The result was disappointing and I assumed that one tiny ant might not have been sufficient to taste something. So, after the aforementioned talk, I approached him and told him I could not replicate his experience. Showing him the picture on iNat, he responded: ‘It was an ant queen you ate, they apparently don’t develop this taste.’
Now I feel bad for having eaten a queen…