Dee Romano, age 11, of Mission Viejo, Calif., for her question:   

 HOW MANY QUILLS HAS THE AVERAGE PORCUPINE?

The average porcupine has about 30,000 prickly quills. However, now and then he loses a few and it takes time for new ones to grow in. He often defends himself by lashing out with his tail, and when this happens some of the quills get stuck in his enemy's flesh. The spikes are set loosely in his skin and sometimes come out easily for no good reason at all.

Though the porcupine seems to be covered with spikes, his coat is actually a mixture of hair and quills. And the quills develop from tufts of hair. Some people suspect that he can fling them like darts and wound his foes from a distance. But this is not likely. When forced to defend himself, he lashes his strong tail with all his might. Usually he aims at his enemy's face, where the jabbing spikes do the most harm.

He expects to lose a few, but replacements soon bring his average quill quota back up to 30,000.