Cacti have many other uses. They are used for human food and as fodder for animals, usually after burning off their spines. In addition to their use as psychoactive agents, some cacti are employed in herbal medicine. The practice of using various species of Opuntia in this way has spread from the Americas, where they naturally occur, to other regions where they grow, such as India.
Cochineal is a red dye produced by a scale insect that lives on species of Opuntia. Long used by the peoples of Central and North America, demand fell rapidly when European manufacturers began to produce synthetic dyes in the middle of the 19th century. Commercial production has now increased following a rise in demand for natural dyes.
Cacti are used as construction materials. Living cactus fences are employed as barricades around buildings to prevent people breaking in. They also used to corral animals. The woody parts of cacti, such as Cereus repandus and Echinopsis atacamensis, are used in buildings and in furniture. The frames of wattle and daub houses built by the Seri people of Mexico may use parts of the saguaro (Carnegiea gigantea). The very fine spines and hairs (trichomes) of some cacti were used as a source of fiber for filling pillows and in weaving.
