Why are hummingbirds immune to Mountain View trumpet plants?

In a Q&A column, Joan Morris addresses two hummingbird-related questions and one about an animal ranch. Warren Snaider of Mountain View asks why hummingbirds land on Angel’s Trumpet (a highly toxic plant). Morris explains that hummingbirds and some moths feed on the nectar without ingesting poisonous parts, and their leaf-licking is likely about dew or tiny insects. Kathryn Riley asks how to keep ants away from a hummingbird feeder; Morris recommends ant moats filled with water and suggests dish soap to deter crossing, along with regular cleaning and checking for alternate ant routes. Bill and Judy request info about exotic animals near I-680 and learn the Seeno family uses them for weed and pasture control.