My Science School

            Most of the birds that we see around us are perching birds. They have four toes on each foot, three of which point to the front and one point backwards. This enables the birds to perch on leaf stems, telephone wires and even thick branches. The tendons in the feet of perching birds make the toes flexible and allow the birds to bend their toes to grasp the perch tightly. If any movement disturbs the balance of the birds, even while sleeping, their feet automatically tighten their grip on the perch thus preventing the bird from falling off.

            The buzzing sound made by the bees is due to the rapid beating of their wings. The rapid beating of the wings creates ripples in the air which produces the sound. All insects fly by beating their wings. But some insects, like the butterfly whose wings beat slowly- 6 to 10 times every second do not produce a buzzing sound. Other insects such as the mosquitoes with very small wings produce very little sound which can be heard only when it is close to our ears. However, the wings of bees are large and they beat very fast – 300 to 40 times every second. This produces the buzzing sound that is clearly audible.

 Snakes are unable to sniff the air through their noses quickly enough to follow the scent of their prey. To do that, they depend on a special organ called Jacobson’s organ located deep inside the upper surface of mouth, which detects odours. By flicking the forked tongue in and out rapidly, the snake picks up odours and puts it on to the Jacobson’s organ. The amount of odour picked up by each tip of the forked tongue also provides information about the direction of the prey.

 Bats are flying mammals. However, unlike birds which can fly and walk as well, bats have lost the ability to stand on their feet or walk. Evolution has modified their forelimbs to support them in air. At rest, the easiest posture for them to adopt is the ‘head down’ posture. They hang on to branches by means of special claws at the end of their limbs.