Researchers at Germany's Max Planck Institute recently published findings of a cross-cultural study of people's spit. "(W)e can get more insights into human populations (from saliva) than we would get from just studying human DNA," the team's leader told Reuters in February. The study's main conclusion was that spit content does not vary much around the world, even given regional differences in diet.
Spanish researchers at Autonomous University of Madrid reported in February that wolves (and almost surely dogs), when relieving themselves, deliberately seek out the most conspicuous places they can find (both as to sight and smell), to assure maximum territorial signaling. Male wolves prefer tall trees (and dogs, prominently located fire hydrants) and try to leave urine as high up as they can to increase its wind-carry, according to a Discovery Channel summary.
Biologist Michelle Solensky, of Ohio's College of Wooster, reported late last year in the journal Animal Behavior that male monarch butterflies are such calculating inseminators that they even decide the optimal level of sperm necessary for reproductive advantage. While injecting fluid, the male can "selectively" determine how much of it will be fertility cells, depending on how much residual sperm the female holds from previous suitors (and thus to always inject more than the other guys did). Solensky told New Scientist magazine that the penis acts as a kind of "dip stick" to check the quantity already present.