Latest species to invade Houston is an icky super-long predatory worm Latest species to invade Houston is an icky super-long predatory worm They get their name from their "hammer" head. Like red ants and killer bees aren't bad enough, there's another invasive species in Texas that has slithered into Houston: an extra-long worm — it can be nearly a foot long — disgusting on its own, but also predatory, in that it eats earthworms, which are essential to maintain healthy soil. It's called a hammerhead flatworm, and The Texas Invasive Species Institute confirms that they're starting to be spotted in the Houston area. The species is quite established in Southeast Texas.