but marc valitutto showed us pandas understand commands.hing good is about to happen- generally involving apple slices. then, on cue, the bear volunteered its arm, through the bars, to a metal tray and gripped a handle. it's having a blood test. >> valitutto: all of the pandas, the adult pandas here, arely tor their arm for a blood sample. it really helps us to prevent the animals from having to be anesthetized and allows the animal to be an active participant in their health. >> pelley: i've seen people throw a bigger fuss than he did. >> valitutto: they're incredibly complex creatures, just like many other bear species or carnivorous species like dogs and cats. >> pelley: like dogs, pandas come at the sound of their name. they know their day will start with apples and continue at the enless bamboo buffet. but success in captivity does not necessarily mean salad days for the species. to thr gic must come home to the wild. >> melissa songer: this is really an exciting time, because they're doing so well in captivity. and we can really consi