What provide shelter to birds, squirel, bat, monkeys at night?

What does provide the centripetal force to a car taking a turn on a level road?

Wings of bird and bat are

What is the number of air sac present in bird?

A man standing in the midst of a field observes, a flying bird in his north at an angle of elevation of 30^@ and after 2.5 minutes he observes the bird in his south at an angle of elevation of 60^@ . If the bird flies in a straight line all along at a height of 60sqrt3 metres, what is its speed?

What is common in whale, bat and rat ?

What is Bird-flu?

What is common in birds and mammals?

What is the main excretory product in bird?

What does self incompatibility provides for a plant ?