Complex sentence: Like all insects, wasps have a hard exoskeleton which protects their three main body parts, the head, the mesosoma (including the thorax and the first segment of the abdomen) and the metasoma.
Split into simpler sentences: Like all insects, wasps have a hard exoskeleton. This covering their three main body parts, the head, the mesosoma (including the thorax and the first segment of the abdomen) and the metasoma.