Rough earth snakes (Haldea striatula) are the most common nocturnal snake in my hometown, Temple, TX. After a good rain, these fossorial and secretive snakes get flooded out of their burrows. Sometimes they will somehow even squeeze through the rubber seals on the bottom of my front door, and on occasion I’ve found a cute squiggle struggling to slither on the slick tiles. Rough earth snakes primarily feed on earthworms and small soft-bodied invertebrates, spending most of their life in moist soily substrate underneath loose logs and rocks. Because of their tiny size (~ 20cm long) and simple coloration this species is often overlooked, but I find their small heads and pointed snout endearing. The individual pictured above was one of the largest and thickest I’ve encountered, likely an adult female.. Along the same trail, many large wolf spiders were within sight; young earth snakes probably often fall prey to the predatory arthropods.
The smooth earth snake (Virginia valeriae) is another diminutive nocturnal snake, formerly thought to be most closely related to the rough earth snake (Haldea striatula), but since then has wavered in its place in the natricine phylogeny. Due to variation in color across their range and their small size, sometimes these two taxa can be mistaken for one another. As their common names suggest, rough earth snakes have keeled scales which are noticeable to the touch, while smooth earth snakes are more glossy. If looked at carefully, smooth earths can also be differentiated by having six upper labial scales instead of five, and two internasal scales as opposed to one. When photographing this individual, I noticed that the lower part of both irises was dark, in contrast to bright orange on top. At first I thought it was an artifact of my flash, but after watching the snake move its tiny eyes around (~2mm in diameter!), the irises were really bicolored. I’ve never given much thought to iris color in herpetofauna, but I will be sure to take note of it from now on.
