Chimpanzees love to eat honey from a variety of bee species, including African honeybees (Apis mellifera) and stingless bees (Melipona, Meliponina, Meliplebeia, and Trigona spec.). Chimpanzees use stick tools to dip into the honey of stingless bees, but they raid the much larger hives of honeybees by rapidly reaching into the nest to rip out a comb before fleeing. African honeybees will fiercely defend their hives by stinging any intruder, including large apes. Humans use fire and smoke to gain access to both wild and domestic beehives. It is unknown when humans started using fire. The oldest evidence from Wonderwerk Cave in South Africa is dated at 1 million years ago, though it is conceivable that the use of fire is as old as the genus Homo (2 million years). Honeybees react to smoke by engorging themselves with honey, and the smoke severely limits pheromone communication among the bees. Thus, approaching a beehive with an ember wrapped in dry grass or leaves to generate continuous smoke allows humans to harvest large quantities of honeycomb and brood comb (for extra protein and fat). Humans are the only species capable of harvesting honey in such quantities. It has recently been proposed that humans have been raiding honeybee hives for possibly more than a million years. This hypothesis is supported by the phylogenetic analysis of two distinct lineages of the African greater honeyguide (Indicator indicatoer), a bird that lives symbiotically with humans. The greater honeyguide points out the location of beehives so that humans can raid the hives and make wax comb available to the bird, the only vertebrate capable of digesting wax. Living hunter-gatherers in Africa and Asia report that honey is among their most favored foods. See honey.