Is a grub a scavenger

Apparently there are no 4-legged insects....then what is in my backyard? Are Polychaete hermaphrodites? Which bed bugs can lay eggs under your skin? What is a carpet mite? What are the characteristics of phylum nematoda? Are inchworms harmful or just pesty indoors? What is a contest to determine the winner of a game or contest? What skeletal structure does an octopus have? What bugs make webs? What are the three major classes of cnidarians? Where is the second anemone in winter range in mini ninjas? What creature that can carry out metamorphosis? What trophic level is an insect? Which bug zappers are most effective on gnats? Why do caterpillars need to shed their skin when they grew bigger but we humans do not? What type of beetle is black with orange spots on its back about the length of a quarter and about a half an inch wide? Can you get ring worm from other people? How do bees poison their victims? What is the phylum of a hydra? What kills mosquitoes?