Thrips live on plants. They suck the sap out of the leaves, and the affected areas often appear to be shimmering because air enters into the empty cells. Some thrips are considered pests. The thrip eggs are laid within the plant tissue with a saw-like ovipositor. The male thrips are very rare; therefore, the eggs develop without fertilization. Thrips go through four larval stages.
Thrips are good fliers, but they only fly on calm, warm summer days. They are predominantly an outdoor phenomenon; however, they are also seen on greenhouse plants and indoor plants and can sometimes stray into houses in large numbers.
They crawl into narrow crevices and you can often find dead thrips behind wallpaper, behind the glass of images and similar places. Some thrips make little awkward leaps hitting the abdomen into the ground or whatever surface, they are on. This is reminiscent of fleas.