Sandra Proctor, age 10, of WinstonSalem, NC  for her question:

What use is a camel’s hump?

When the desert journey is over, the camels may be put out to pasture. For days or even weeks they have their fill of hay and grasses. The desert days, when food rations and water were short, are all forgotten and the big animals build up their bodies. When they can, they eat extra food which is turned to fat and stored in the hump.

A camel who is ready for a new desert journey has a firm, high hump. This built‑in pantry is stuffed with fat which will be turned into energy on the long, hungry journey ahead. At the end of each day, he will be fed perhaps a handful of dried dates and, when he comes to an oasis, he may get a little hay. At journey's end, the ,hump will be soft and, maybe sagging over to one side. Much of the stored food has been used up. 

But it will be stuffed full again after a few days of camel banqueting,