Some species of ants deposit individual atoms of zinc on their teeth to make them strong, durable and sharp.
Ants have teeth, called mandibular teeth, which are actually outside their mouths, on their mandibles that clench them together. They must be sharp to compensate for their very low bite force. In order to make them sharp, some species have evolved to tilt their mandibular teeth with zinc, which they sequester from their diet.
In a recent study, Robert Schofield, of the Department of Physics at the University of Oregon, and his colleagues used a process called probe tomography to examine the atomic structure of the tips of ants’ teeth, to determine their composition. . They discovered that zinc atoms bind to proteins in the ant’s mandible. Zinc can represent up to eight percent of the total weight of each mandibular tooth.
Adult Ant Teeth
The mandibular teeth of the ant are initially very soft. Zinc comes in in the early days of adulthood, making teeth about three times harder, durable, but not brittle. Schofield says that by comparison the first teeth are about as hard as plastic, but when zinc is added the hardness is more like that of aluminum.
Ants do not have a defined number of mandibular teeth, this varies between species and individuals. But they’re not the only ones with such teeth. Schofield says that spiders, beetles, and millipedes are all very good at taking zinc from their diet and using it to make sharp teeth.
Produced and written by Mark Crawley