Physical characteristics
Apordiformes derive their names from a Greek word a pous which literally means without foot. And true to the name, they have small feet with short legs. Majority of birds making this group are unable to walk, and so cannot escape fast by simply walking and then flying in case they land on the ground.

They more than make up for their weak feet by their thick shoulder bones and long powerful breastbones which make them very strong fliers. And they can move their heads pretty quickly because of their powerful neck muscles.

Owing to physical and behavioral differences in the order Apordiformes, three families can distinctly stand out.

Swift family (Apodidae) consists of birds that eat sleep and mate in the air. Also called typical swifts, these birds have long pointed wings. They measure 9 to 25 cm from head to tail. They weigh 5 to 205 grams. The swift has a large gape but a short bill. When hunting for prey, the swift opens its mouth to let in its food.

The feathers of this bird are black or brown, forming white patterns in some birds. Male and female birds share the same plumage, if you like feather color.

The next family is the tree swift, which belongs to the Hemiprocnidae family. They can perch in trees unlike swifts and range from 15 to 30 cm in length. They weigh 21 to 79 grams. This kind of birds has flat bills, whisker-like bristles and large gapes.

Another name for tree swifts is crested swift, a name they got by virtue of the fact that they have a crest or lump of feathers on their foreheads. They have brown or light gray plumage though other colors may blue, green and also white. Unlike other groups, the plumage of the male and females are not similar.

The last family in this order is the Trochilidae family, whose main representatives are the hummingbirds. They got their name from the sound that they make by quickly vibrating their wings. They have the reputation of being able to fly backwards and hover, which they achieve by staying in one place as they flap their wings.

They range in length measure between 5 to 22 cm and weigh from 1.0 to 21 grams. Apart from having long thin bills, they also have long forked tongues.

They are always billed as the liveliest members in the apodiformes in terms of colors. The colors of the plumage include green, pink, red, yellow and purple. Usually, the male birds are more colorful than their female colleagues, a feature that they use in hiding their young ones from predators

Diet
Swifts are known tree insectivores. While preying, they leave their mouths open so that whatever prey just falls in there. They perch on trees and lay in wait for the preys which are mostly flies, bugs and ants. After catching the prey, they swallow it wholesomely. The purpose of their long tongues is to drink nectar.