>>12008603In the OP picture an ant grooms an aphid for honeydew and drinks it in mutual symbiosis. I was thinking, if there is any example of taste communication, it's probably something like this. Organism A produces something and Organism B consumes it; the taste communicates some kind of information.
In fact I would bet that the ant in the picture does derive some information from the taste of the honeydew though I wouldn't count it as communication unless the aphid changes the composition of the honeydew for the specific purpose of communicating with the ant.
Other possibilities I can think of might be some social animal, probably hymenopterans, doing something similar among members of the same species, or some animal that grooms each other communicating through the taste of sweat.
Honestly there are so many weird forms of chemical communication out there, like plants being eaten by caterpillars summoning parasitic wasps, I would be shocked if taste communication WEREN'T a thing, even if it's not yet known to science.
