Xylophis captaini was probably originally an inhabitant of the rich rainforests of the western foothills of the Western Ghats mountains. It is still found in remaining patches of rainforest here, but it is mostly encountered in the plantations and gardens that have largely replaced forest in this region.
X. captaini hides (and perhaps feeds) in the soil and was only described in 2007, so little is known of its ecology. During the daytime the snake is generally found only by digging and turning over surface soil and leaf litter in rich, shady and moist habitats.
As with many other burrowing snakes, the scales of X. captaini are iridescent, which seems to be a by-product of having scales with minute ridges adapted to easily shed moist soil.
The details of its diet are not completely known, but includes at least small earthworms.
No reports of predation are known, but predators probably include other burrowing vertebrates.