They love wet soil and feed on decayed organic matter in the soil. They may attack tender new growth but prefer material that is already dead. If you have them you could be overwatering. They are not a big threat but since nobody likes bugs in the house try treating the soil with Pyrethrum or Malathion at the concentrations mentioned earlier. Transplanting to new sterile soil after washing the roots is another way to control them.
Thrips are small, thin pests, the young being yellow and the adults brown or black.
The adults are winged and tend to fly around the plant when disturbed. They rasp the plant tissue and suck the juice, leaving silver specks on the surface. Their black droppings are small but you can still see them on a badly infested plant. Females leave a small scar on the tissue where they deposit their eggs. Decent control can be achieved with the same materials used on aphids.