I think I'll make this a new feature, since all kinds of
interesting things pop up in my Google Scholar searches. Here's
one: Urine makes the difference : chemical communication in
fighting crayfish made visible Thomas Breithaupt and Petra Eger
In this study, they were interested in chemical communication
between crayfish who were fighting with each other. So they
blindfolded the crayfish, and then used fluorescent dye to see
the urine. Evidently, they fan the urine toward each other using
their gills or maxillipeds. Here's part of the abstract:
Aggressive behaviour is effective in intimidating blindfolded
opponents only in conjunction with urine release: receivers
decrease offensive behaviour and increase defensive behaviour.
Aggressive behaviour alone does not intimidate opponents. The
loser of a recent fight is deterred equally well by a familiar
and an unfamiliar opponent. Hence, in crayfish, individual
recognition of the urine scent of a dominant individual does not
appear to be significant for the maint