Their colour helps grasshoppers hide from enemies. ©Getty Images

Their colour helps grasshoppers hide from enemies. ©Getty Images

Grasshoppers and crickets are insects. They are invertebrates, which means they have no backbone. A hard shell called an exoskeleton covers the body.  'Exoskeleton' means 'outside skeleton' because insects do not have a skeleton inside their bodies like mammals do. 

There are two groups of grasshoppers; short-horned grasshoppers which have short antennae, and long-horned grasshoppers which have longer antennae. There are several thousand kinds of grasshopper, and one kind of short-horned grasshopper is called a locust. Grasshoppers and crickets live in most parts of the world, except where it is very cold.

Body

Crickets are active at night. © Getty images

Crickets are active at night. © Getty images

Their bodies have three main parts: the head, the thorax and the abdomen. Two antennae (feelers) grow from the head, longer in crickets than in grasshoppers. They have five eyes and can see to the front, to the side, and to the back. Grasshoppers and crickets have six legs with strong leg muscles, and their back legs are big so they can hop about 20 times their body length.  Most have two pairs of wings. Insects breathe through holes, called spiracles, along the sides of the abdomen and the thorax. Grasshoppers make a noise by rubbing a hind leg against a wing, causing it to vibrate and make a sound, but crickets make a noise by rubbing their wings together.  Grasshoppers are diurnal (active by day) and crickets are nocturnal (active at night).

Brown grasshopper protects itself using camouflage ©Getty Images

Brown grasshopper protects itself using camouflage ©Getty Images

Diet

Most kinds of grasshopper eat plants, but some long-horned grasshoppers also eat dead animals or catch and eat other insects. Grasshoppers can be a pest to farmers when they eat farm crops.  Crickets are omnivorous, eating plants and other animals.

Threats

Beetles, birds, lizards, mice, snakes, and spiders prey on grasshoppers and crickets. Grasshoppers protect themselves from enemies by jumping or flying away. They also bite their enemies with their strong jaws. They use camouflage too. Their colour helps them hide on leaves if the grasshopper is green, or on rocks or on the ground if the grasshopper is brown.

Life Cycle

Adult grasshopper emerging from final moult. ©Getty Images

Adult grasshopper emerging from final moult. ©Getty Images

Females have a strong, sharp ovipositor (say oh-vee-poz-uh-tuh), which means 'egg placer',  at the end of the abdomen. Eggs come out of the female's body through the ovipositor.  After mating with a male, a female lays eggs in sand or under leaf litter. The eggs are held together by sticky stuff from inside the female's body. A group of eggs is called a pod, and usually the female lays about 20-25 pods.  The places where pods of eggs are laid are called egg beds. If there is warmth and dampness, the eggs hatch in about 2 weeks.  If conditions are not right, the eggs can ‘sleep’ until it is warm and damp, then develop.

When they hatch,  the are called nymphs, and look like adults but they don't have wings. As they grow, the nymphs shed their exoskeleton. This shedding is called moulting.  Each time they moult, there is a new, bigger exoskeleton underneath. This is because insects don't have skin that stretches as they grow. The nymphs moult up to six times.  After about 40 to 60 days they make the last moult and are adults with wings.  Adults live for about two months, depending on the weather.

Locusts are a type of grasshopper ©Getty Images

Locusts are a type of grasshopper ©Getty Images

What is a locust?

A locust (say low-cust) is a type of grasshopper, but a locust can change how it looks and behaves. There are different kinds and sizes of locust found in different countries.

When food is plentiful, locusts live on their own, just like grasshoppers, but when there is lots of food, their numbers increase.  That means when the weather changes, plants die down and there is little food, there are lots of locusts all crowded together.  This signals them to go through changes: their colours turn to bright yellow or black and their eyes bigger. Their back legs are now bigger so they can sit tall and look around. Their wings are longer so they can fly for many kilometres. These physical changes are accompanied by a disastrous behaviour change. They take off in huge groups , looking for food.  

Locust swarm ©Getty Images

Locust swarm ©Getty Images

Swarms

Locust ©Getty Images

Locust ©Getty Images

A huge group of locusts is called a swarm, and a swarm can be billions of locusts. Swarms fly up to 130 km a day, and the locusts eat all the plants in their path. After they finally run out of food, the locusts separate and change again. Locust swarms occur in many countries.

When locusts swarm, it is terrible news for farmers. The locust swarms will leave farms with nothing left growing, all crops gone, and farmers with no income. A locust swarm is a disaster, it can cover hundreds of square kilometres. When this looks like it may happen, a government tries to spray the nymphs before they can fly.

Read more about grasshoppers

http://insects.about.com/od/grasshoppersandcrickets/a/10-Cool-Facts-About-Grasshoppers.htm

Read more about crickets