Standing on Guard...
I like to watch.
Behaviour, that is. Rather than searching out an elusive species to add to some personal "I've-seen-that" list, I'm much happier watching what organisms do. And even humdrum, run-of-the-mill, species do some very intriguing things.
For example. watching a male Canada Goose stand guard over mate and nest poses some interesting questions about ourselves. Everyone has a personal space, a territory, that they hold inviolate, and many organisms, even such seemingly unsuited ones like butterflies and fruit flies, are quite adept at guarding territory.
Whether it is for some resource, some particular space, or some presumed ideological difference, territoriality is one of the driving forces of all life. Humans are no different, though our ideological differences seem to form too large a part of our territorial acquisition urges. Still, guarding is one of those recognizable behaviour sources that answer the interesting "why" questions.
Other behaviours to watch for include those associated with foraging, whether it be for sustenance or for mates, and those associated with predator escape mechanisms (such as the abilty to choose matching backgrounds and be perfectly still).
Foraging behaviours can be incredibly varied and intriguing such as the penchant for butterflies to visit wet sand or mud along roads or stream sides for mineral salts. Even insects need salt licks!