No, "no-seeums" (as I understand) are flying insects, like tiny gnats. Chiggers are tiny mites (arachnids, not insects) that burrow into the skin and cause itching, raising a small (approx. 5 mm) red bump. The critters are typically picked up in grassy/woody areas, and are not visible to the unaided eye. It's typical of a weekend camping trip to get home and find that several of them have taken advantage of the free food and lodging that your body provides them.