<P>The desert Southwest <BR>is full of sounds.<BR></P><P>Skitter, skitter, scratch. <BR>A scorpion is crawling. <BR>Pop, pop, pop. <BR>kangaroo rat is hopping. <BR>Tsk, tsk, tsk. <BR>A rattlesnake is <BR>shaking its tail.<BR></P><P>But the spadefoot toad <BR>is quiet in her <BR>underground burrow, <BR>listening for one sound <BR>in particular... <BR>What is that sound? <BR>And what will the <BR>spadefoot toad do <BR>when she hears it?<BR></P>