Fat edible caterpillars or mopani worms. In rural areas they are collected from trees but in town they have to be bought. Caterpillars are prepared for eating by squeezing out the gut contents before they are fried in their own body fat or boiled in a little water. Most of the caterpillars are dried so that they can be stored for use throughout the year. Dried caterpillars may be eaten dry as a snack or rehydrated and cooked in a little water before they are fried in oil with onion and tomato. They may be served with pap (maize meal porridge), onion and tomato gravy and atchar (chili sauce). The mopane worm is a large caterpillar that feeds on the mopane tree, Colophospermum mopane. The adult stage is a large and attractive Emperor moth (Family Saturnidae). The worm is an important source of protein and income to many people. However, the trade is threatened by over-harvesting, and mopane worms are now rare or extinct in some areas where they were once common.