Scientists in England have discovered that the leaf cutter ant uses multiple antibiotic-creating bacteria as a week killer to protect its fungi gardens that feed the colony from bacteria and fungal infections, much as humans use multi-drug therapies to fight disease.

The ants, Acromyrmex octospinosus, are native to the southern United States, South and Central America. The ants studied came from colonies in Trinidad and Tobago.

They are naturally infected with actinomycete bacteria that live on them in a mutual symbiosis. They then use antibiotics produced by these bacteria as part of a 'pesticide regime' in colonies and their carefully-tended fungus gardens, to keep down unwanted growths of other fungi and bacteria.

The research was led by Matt Hutchings at the University of East Anglia in the United Kingdom. It was published in the journal BMC Biology.