They have tiny brains.  But if you measure intelligence by the "encephalization quotient" of brain-to-body ratio, the hummingbird is the most intelligent of all animals --including us!  Not convinced?

Weighing less than an American nickle, the hummingbird is a stripped-down jet-plane of a bird -- carrying only enough fuel for a few hours of flight and devouring up to five times its own weight in nectar every day.  In cold weather it can shut down its jet-engine metabolism, dropping body temperature from 105 to 54 degrees (F). Flying backward or hovering in mid-air makes the hummingbird seem as brainless as a dragonfly, but in spite of its diminutive size, this is bird packs a lot of intellectual firepower.

Hummingbird songs are as complex as any songbird -- extending into the ultrasonic range.  The birds may visit 1000 flowers a day, and their foraging efficiency is greatly improved by an accurate recollection of which plants contain the most nectar and how recently they were visited -- showing Hummingbirds are capable of the episodic memory that is thought to signify human awareness.  Hummingbirds have terrible tempers, and will viciously fight each other for territorial rights -- battles that can be decided within milliseconds.  Nerve signals travel slowly, and humans require huge chunks of time to merely register a stimulus.  Because of its smaller size, Hummingbird brains are capable of lighting-swift thoughts -- and if you measure life by counting heartbeats, their life-span is comparable to ours.  However, they must surely hold us slow-witted mammals in contempt.  And why not?  In all of nature --the Hummingbird owns the swiftest mind.