Insects: Facts on frightening ramps that represent more than half of the world’s animal species

Insects have six legs. These legs are attached to the central part of the body of an insect, the thorax, and they are controlled by thorax muscles.

Many insects have legs that are good for performing specific functions, such as leap, swimming, digging or maintenance of prey. Tigers beetles, for example, have a lean and fast movement legs that are good for running. The locusts have Giant rear legs This helps insects to get started and jump long distances. And the prayer mantis have Special entry legs who help insects to hold prey or friends.

Insects have hearts, but they be very different human hearts. Insects have what scientists call an open circulatory system, in which their “blood” – in fact a substance called hemolymph – does not travel through closed veins or arteries. Instead, it flows into different parts of the body, bathed the organs inside.

Insects have a major shipwhich is mainly like a giant tube, which flows from their heads to their tail along their back. The “heart” is the section of this ship which crosses the abdomen (the back of the body of the insect). There, the container is divided into rooms with valves and muscles which ensure the flow of hemolymph in one direction, towards the chest and the head. Beyond the abdomen, the container becomes a smooth tube that empties near the brain. The hemolymph springs on the organs and muscles of the insect head, bringing nutrients, salts and other chemicals. The fluid then makes its way through the body, collecting the waste and ends up returning to the opening of the heart at the back of the abdomen.

The hemolymph plays several important roles. Liquid kills parasites, seals injuries and produces stinking and raw taste to scare predators. In some insects, hemolymph helps keep the body at a stable temperature by moving the heat. But unlike our blood, the main goal of the hemolymph is not to move oxygen around the body. Insects do not breathe in the lungs. Instead, they use spiracles or holes, so they don’t need a special liquid to transport oxygen from one organ to another.

Like other animals, Insects sleep. Insects have no eyelids, so they cannot physically close their eyes to a nap. But they enter a state of rest and behave in a way that scientists call sleep. Like us, insects remain relatively motionless and lower their body temperature when asleep. Many insects are difficult to wake up, and there are evidence that some have preferred sleep positions.

Like most animals, insects need to sleep to Help their brains work better. Experiences show that some sleeping insects find it difficult to remember where things are and communicating with each other. It can make them difficult for them to find food and survive.

For example, Bees remember how to move around Better after a good night’s sleep. The researchers released the bees in different places and followed their flights at home. Most bees slept longer than usual after this trip, but those who slept are less difficult to remember their path the next day.

The bees also make a special “Waggle dance” to point other bees in the right direction to find food. But when they don’t sleep enough, Their Waggle dances become sloppy And their niche comrades find it difficult to find food. Bees like to sleep in the dark, suggesting that as in humans, Their sleep follows a circadian rhythm -That is to say an internal clock of day and night cycles. Bees compensate for a bad night’s sleep by Sleep more deeply the following night. This suggests that sleep is really important for these insects.

Scientists think that at least some insects feel pain. In a 2022 studyFor example, researchers have shown that bees prefer to visit feeders filled with sugar water that were at room temperature rather than very hot feeders. This suggested that bees avoid heat, but it has not proven that they consciously try to avoid being burned. To find out, scientists made water in the feeders at room temperature less sweet. The bees then preferred the hot feeders. This suggests that the bees could choose to overcome their aversion to the uncomfortably hot surface if the reward – the sweet treat – was large enough.

Scientists see this as a sign that insects can be sensitive or capable of thinking and feeling. A country has even adopted a law Define sensitivity in animals. This law lists eight signs that an animal may feel. The first is that pain relievers change the way they react to things that could cause pain in us, as being stung or burned.

It turns out that insects also have revealing signs of pain. Scientists looked at 300 experiences And found that flies, mosquitoes and cockroaches met six pain criteria. The bees, the wasps and the ants met four of these requirements, and the butterflies, the butterflies, the locusts and the crickets encountered three.

Given the number of insects, Scientists have not tested if most feel painBut it is clear that the brain and the behavior of insects are more complex than we used to think.