Science Past from the issue of October 21, 1961

‘ALARM CLOCK’ BRINGS SNAKES TO SURFACE — A built-in “alarm clock” apparently helps a brightly-banded little desert snake come to the surface at night after he has buried himself to escape the day’s heat…. It had been noted that these snakes, which remain buried in the sand most of the time, appear to come to surface virtually in unison over a wide area every night. It was thought that they followed a rising heat barrier in the sand which rises as the sand cools off each night. Laboratory studies … have indicated that there may be a little more to it than this. The investigation has suggested that the snake has a biological alarm clock which “wakes” him up about 23 hours after his last emergence at the surface.