Rennee Lanham, age 11, of High Point, North Carolina, for his question:

Does a sidewinder loon to the left or right?

This fellow, of course, is a rattlesnake, a deadly viper. What's more, when he strikes he moves very fast    too fast for us to observe how he does it and also tend to safety precautions. It is best to solve this problem with indirect evidence from the records. There we learn that the sidewinder travels by looping his snaky body from side to side. Aside to side motion suggests both left and right.

Actually, the desert viper loops both left and right. He travels with head forward and his body forming S shaped curves, looping to the left and right sides of his path. With each coiled motion, he stretches his head forward and places only his neck on the ground. His body follows, section by section, in an S shaped curve with the left and right loops held above the ground. The sidewinding motion is very graceful and also very efficient in sandy locations where other snakes fail to get a necessary grip on the ground.