They probably evolved from oligochaete worms. Centipedes dwell in damp places under old logs and stones. They are carnivorous, eating mostly insects. They are highly segmented, and have one pair of legs per segment. The first trunk segment bears poison fangs .
Centipedes are very dangerous, and their bite is extremely painful.
Millipedes share the same habitat as centipedes, but they are mostly herbivorous, feeding on decaying vegetation in the leaf litter. Animals that feed on detritus are called detritivores . If we knew all the different insects on Earth, there could be as many as 30 million species. Insects evolved about 200 mya, with cockroaches and dragonflies among the first to appear. Most insects have one or two pairs of wings.