Birds have bones while insects do not have bones. Insect have wings attached to the thorax.
Introduction
Birds and insects are very different from each other. While it is interesting to explore both of them individually, one fact is understood and widely known that there are a lot of species of birds and insects on this planet and many sciences have come into existence just to search all of the species that were and are present in the world at the moment. While insects do fly as well, but are they birds? No, and that is because of the differences that both of these separate classes of creatures share.
History
Birds are very peculiar species that the human race has been jealous of ever since the beginning of time, because birds are able to fly and humans are not. They have inspired man to create airplanes. But can all birds fly? No, and the chicken is a perfect example of that. Not only the chicken, but the ostrich, emu, cassowary, rhea, kiwi and penguin are well known examples of birds that cannot fly. Like birds, there are some species of insects that cannot fly as well, such as the grasshopper. But both birds and insects dominate the skies, and have always done so since the beginning of time. There are many differences between birds and insects. Birds are vertebrate animals, whereas insects are invertebrate. Also, only a small number of bird species are flightless, but as far as insects are concerned, there are many flightless insect species on this planet such as ants, termites etc.
Features
Although birds and insects both can fly, they both do not have the same body structures or characteristics. Birds are vertebrate animals that are feathered, bipedal, egg-laying and warm-blooded whereas insects belong to the class of arthropods and posses an exoskeleton with a body that is divided into 3 parts (thorax, head and abdomen), jointed legs in a pairs of 3, two antennas and compound eyes. Also, there is a huge difference in their size as well. While there are some bird species that are small, still they are not as small as insects. An insect’s size ranges roughly from 2cm to 28 inches, whereas a bird’s size ranges from 2.5 inches to 9 feet, so generally birds are bigger than insects. Also the growth patterns of both the birds and the insects is completely different from each other since birds grow in a single form throughout their life, insects go through metamorphosis and change their form to become adults.