1923] Atsatt: Behavior of the Leaf -nosed Snake 305 



sunlight after forty-five minutes of activity during exposure to light. 

 The snake crept into the sand in three and a half minutes, resting 

 three times during that period. Ten minutes later the snake took 

 only two minutes to get entirely into the sand except for an inch of 

 the tail. 



Often, attempts to hide in the sand were not completed and the 

 head only was covered. And often, successful burying of itself in 

 the sand was not followed by any period of quiet and so the animal 

 became uncovered again. 



A few times the snake was observed to use another method of 

 getting into the sand, namely, by digging a hole. "When the snake was 

 originally found on the desert floor, it was under a rock in a small 

 dejoression with a burrow leading to it from the ground surface. On 

 April 13, while the snake was being observed with relation to heat and 

 light, it made four attempts to creep into the fairly compact shallow 

 sand. Each time, the head was covered but was raised again to the 

 surface. Then the snake scooped a hole by turning its head to the 

 right and piling up the sand. This action was not repeated there, 

 but in another spot the animal worked its head in and then up again 

 to the light. When the earth was loosened by the observer, the snake 

 successfully worked its way into the sand within the next few minutes. 



This method of digging a hole Avas used again on April 15 after 

 the snake had been exposed to light for about forty minutes, part 

 of the time to direct sunlight and part of the time to sunlight through 

 a blue filter. The snake made attempts to bury itself in the sand, but 

 each time the head reapi^earcd in the light. A small stone was put 

 in the shadow on one side of the box. Twice the snake started to 

 creep under the stone but did not get its head covered. Then it dug 

 a hole by loosening the sand and turning its head to one side and 

 pulling back the anterior half of its body so as to form loops. The 

 sand held between the head and first loop of the retracting body was 

 dropped when the snake straightened out again. The snake used 

 either right or left side; for instance, right, left, right, right, left, 

 right. With its head at the bottom of the hole thus started, it finally 

 crept into the sand. 



On April 16 the snake was stimulated by blue light. After seven- 

 teen minutes of rather constant motion, including attempts to get out 

 over the top of the box and three attempts to cover its head, the 

 snake started at 4 :03 p.m. to dig in the southwest corner in a shadow 

 cast by the side of the box. Either the posterior third or the middle 

 portion of the body was held tight on the ground. The snake con- 



