If you are a small Anolis lizard sleeping on the end of a twig or a tree frog embryo developing your aquatic paraphernalia, nocturnal snakes are certainly your biggest fear. Three species high in abundance are particularly worrisome: the blunt-headed (Imantodes cenchoa) & yellow blunt-headed vine snakes (Imantodes inornatus), and the cat-eyed snake (Leptodeira septentrionalis).
When I first visited Costa Rica many years ago, Imantodes were the snakes I most wanted to find. They have unbelievable suspensory abilities, capable of looping the body in figures of 8 endlessly and remaining motionless in the air. When outstretched on the forest floor Imantodes cenchoa looks impossibly thin and long, indistinguishable among fallen branches, whereas I. inornatus splays itself neatly across trunks higher up in the forest strata. Imantodes is always a delight to handle, being almost weightless, mellow, and seemingly able to move in any direction midair. As an adaptation to their arboreal habits, the internal organs of Imantodes are located more posteriorly, shifting the center of gravity to free up movement of the head and upper body. Imantodes cenchoa, and probably others in the genus, have an affinity to bromeliads, where they will take refuge during the day and feed on smaller reptilian and anuran visitors that likewise seek shelter. This explains why despite their high abundance and nocturnal prevalence, Imantodes is extremely difficult to find during daylight hours.