Rena humilis, known commonly as the western blind snake, the western slender blind snake, or the western threadsnake, is a species of snake in the family Leptotyphlopidae. The species is endemic to the southwestern United States and northern Mexico. Six subspecies are currently recognized, including the nominate subspecies described here.

The Leptotyphlopidae are a family of snakes found in North America, South America, Africa and Asia. All are fossorial and adapted to burrowing, feeding on ants and termites. Two subfamilies are recognized.