How are humans different from insects?

Answer 1

They are bigger, vertebrates, without an exoskeleton.

They have only two legs, do not lay eggs and do not go through any stages of metamorphosis.

There are lots of other differences.

Answer 2

They have 6 legs instead of 2. Their structural skeleton is on the outside of the body instead of the inside, so they have to shed their entire exoskeleton every now and then as they grow. They have a series of ganglia with control over various parts of the body rather than a completely centralized "brain" as in a human (although more derived insect orders have the ganglia clustered more together into what is often called a "brain", but it is not homologous with the human brain). It is debatable whether this simple system is enough to make insects "self-aware" creatures, while humans are clearly self-aware. They have mostly passive transport of nutrients and air rather than an active circulatory system. Their hearts are elongated structures that move hemolymph around through parastalsis. Because their "blood" doesn't carry oxygen (it is transported through a separate system), the blood does not need hemoglobin, meaning it is not red. Technically, it's called hemolymph and not blood. They don't have lungs. Because of all this passive transport, they cannot get above a relatively small size (or else the innermost tissues would die long before nutrients passively transported themselves to the middle of the insect). Insects normally have wings derived from respiratory tissue, while the wings on species related to humans (bats, birds, etc.) are modified appendages (arms/legs). Insects as a group have been around for hundreds of millions of years, while humans as a species are only a few tens of thousands of years old. Even the oldest hominids are only a few million years old. Insects are r-selected species, so they produce many 100s of offspring throughout the course of a very short lifespan and then provide them little parental care, while humans are K-selected species that live much longer, produce only a few relatively larger offspring, and then use a lot of energy to provide parental care. In addition to differences in anatomy, physiology, and ecology, many people hold spiritual or religious beliefs that identify humans as a special species containing some aspect of divinity not present in "lesser" organisms like insects (i.e. a "soul", "atman", "jiva", etc.) But that leaves the realm of science, so I'll stop there. :)