Calamaria pavimentata

黃頷蛇科，Calamarinae 亞科
Colubridae, subfamily Calamarinae

40 cm

台灣全島與蘭嶼低於海拔 1500 m 以下可見。罕見蛇種。

印度（阿薩姆），西馬來西亞（含刁曼島），泰國，寮國，越南，柬埔寨，緬甸，南中國（海南，福建，廣東，廣西，貴州，四川，雲南，浙江），台灣，日本（琉球群島）。

Small snake; total length up to 40 cm. There are 13 rows of scales, all are smooth and iridescent. Head is small and not distinct from neck, but the shields are large; the prefrontals are enlarged (slightly longer than broad) and there are no loreals, temporals or internasals. Body is cylindrical and slender; tail is short, ending in a spine. Eye is small, bead-like; iris is dark brown to black, indistinct since it blends with dark head, and pupil is round, black, and blends with rest of eye. Tongue is short, with reddish stem and diffuse gray fork tips with dark brown base. Upper head, body and tail are reddish brown to blackish brown. The dorsal shields of the head may show with diffuse light areas, and the lower part of the upper labials is lighter in color. There may be 1-2 pairs of light spots, one light cross band or one pair of light streaks on the nape, and up to 10 longitudinal lines of faded black along upper body and tail. The scales on upper body are dark-edged. Ventral head is light cream. Ventral body and tail are yellow to orange; there is a mid-ventral line of black on underside of tail. Anal scale is entire, and subcaudals are paired.

鐵線蛇為卵生的夜形性蛇類，牠是台灣 黃頷蛇科 最小的成員。因其為 穴居動物 通常隱匿在石縫、土堆、落葉和腐植層中，所以使得牠很難在野外遇見。以小型無脊椎動物為食，像是蚯蚓或小型昆蟲等等。鐵線蛇個性溫馴，遇敵時並不會張口咬人，牠會使用角質呈尖次狀的尾部戳刺來防衛。

鐵線蛇、尖尾兩頭蛇。

其實在台灣的鐵線蛇個體與顏色有不小的差異。目前需要更進一步的研究是否只是 多態性，或是牠們是不同的亞種、種類。