Washington DC, June 26 -- A newly discovered spider in the rainforests of northern Queensland has evolved an extraordinary hunting technique. Researchers say the species uses a powerful spring-loaded silk trap to capture a single type of prey, catching one ant at a time in what they describe as "the ultimate specialization."

The small nocturnal arachnid has been nicknamed the ballista spider after the ancient Roman siege weapon that launched bolts and stones using stored tension. According to scientists, the spider appears to have developed a unique web system designed specifically to capture the aggressive green tree ant, Oecophylla smaragdina.

The discovery and detailed analysis of the spider's hunting behavior were published in the j...