Africa is home to a variety of crops, livestock, and cultural practices. Savannah regions grow grains like millet, sorghum, and maize while the Sahel region closer to the Sahara grows cotton and watermelon. Livestock like cattle, goats, and sheep are raised but seldom killed since animals represent wealth. Large families with many children are valued as they provide security, wisdom, and increase wealth and honor for the family and clan. Religion incorporates belief in a Supreme Being as well as lesser gods and spirits that inhabit objects, and sacrifices are made to receive blessings. Islam arrived through trade caravans and slaves brought from Southeast Asia.