We often use the term “bug” around here for many different types of creepy crawlies - rolie polies, millipedes, ticks, spiders, ants, bees, moths, etc. But, these little mini beasts are not all insects. Insects have special characteristics that separate them from other arthropods. Arthropods are the phylum (large group) to which insects belong along with arachnids, myriapods and crustaceans. They all have things in common, but only insects have this combination of the following features.