Essentially they consumed meat (primarily from Nguni cattle, Nguni sheep (Zulu sheep, Pedi sheep, Swazi sheep), pigs/boars and wild game hunts), vegetables, fruits, cattle and sheep milk, water, and grain beer on occasion. They began to eat the staple product of maize mid-18th century (introduced from the Americas by Portuguese in the late 17th century via the East African coast), it became favoured for its productiveness which was more than the grains of South African native grasses. There were a number of taboos regarding the consumption of meat. The well known, no meat of dogs, apes, crocodiles or snakes could be eaten. Likewise taboo was the meat of some birds, like owls, crows and vultures, as well as the flesh of certain totem animals. The mopane worms are traditionally popular amongst the Tswana, Venda, Southern Ndebele, Northern Sotho and Tsonga people, though they have been successfully commercialized.