"Ten specimens of Boiga irregularis were presented with clean or bloody tampons. The latter were used by women during menses. Trial duration was 60 sec, intertrial interval was 24 hr, and the dependent variable was rate of tongue flicking (a measure of chemosensory investigation). Bloody tampons elicited significantly more tongue flicking than did control tampons. An additional snake is shown attacking and ingesting a soiled tampon, confirming that chemosensory interest was associated with predatory behavior."
"FIG. 1. [SCENE MISSING] (A) A brown tree snake investigates a soiled tampon suspended into its cage. (B) Seconds later the snake bites the tampon. (C) About 2 min following the bite, the snake is shown with only the string remaining unswallowed. This snake then struck and swallowed a second soiled tampon."