A dust mite is very small bug that you cannot see. Even though your room may look clean, he can hide under your bed and make you itchy, sneezy and stuffy.
Ragweed is a tall weed that grows in the summer, in parks and along walking and biking paths. It makes pollen that can make your nose run and your eyes itch.
Cat dander is very small pieces of your kitty’s skin that float in the air; landing on you and in your house. If you’re allergic to it you can get itchy, have trouble breathing, and just don't feel good.
Trees realease somthing in the air that we call pollen in the spring. If you’re allergic to tree pollen it can make you feel like you always have a cold.