Atta insularis is a species of leafcutter ant, a New World ant of the subfamily Myrmicinae of the genus Atta. This species is from one of the two genera of advanced fungus-growing ants within the tribe Attini. This species is the largest and most notable species of ant of Cuba. A. insularis is unique to Cuba, and has great polymorphism. Its workers specialize in different activities. The warriors have remarkably large heads. They prefer to work at night, although they do by day, more if on cloudy days. This species is a pest of citrus, coffee, and various Pinus species.