It's been known for decades that animals such as chimpanzees seek out medicinal herbs to treat their diseases, in order to alleviate their pain (NOTE: Subscribers can till listen to this story, as well as Whitley's commentary on it). Moths, ants and fruit flies are now known to self-medicate. Dogs and cats lick their wounds because their saliva has antibiotic properties.
In recent years, the list of animal pharmacists has grown much longer, and it now appears that the practice of animal self-medication is a lot more widespread than previously thought.
Ecologist Mark Hunter says, "When we watch animals foraging for food in nature, we now have to ask, are they visiting the grocery store or are they visiting the pharmacy?"
Animals "vaccinate" themselves and their offspring as well. House sparrows and finches add high-nicotine cigarette butts to their nests to reduce mite infestations. Wood ants incorporate an antimicrobial resin from conifer trees into their nests, preventing microbial growth in the colony. Parasite-infected monarch butterflies protect their offspring against high levels of parasite growth by laying their eggs on anti-parasitic milkweed.
And just like human parents, Hunter says, "Animals like fruit flies and butterflies can choose food for their offspring that minimizes the impacts of disease in the next generation."