SAN ANTONIO – An invasive flatworm has made its way into Texas and has been found throughout the San Antonio area, experts say. So I reached out to The Texas Invasive Species Institute and sent some pictures for confirmation. According to the Texas Invasive Species Institute, the tiny black worms made their way into the United States and were first spotted in Florida in 2015. In addition to the New Guinea flatworm, TISI also warned of another invasive species that can carry rat lungworm -- the Black Velvet Leatherleaf slug. (Texas Invasive Species Institute)The hammerhead flatworm, also known as the hammerhead slug is another invasive species in Texas.