Scientists think play is valuable, but they’re not quite sure why
By Chris Woolston Anyone who has ever chucked a tennis ball in the general vicinity of a border collie knows that some animals take play very seriously. The intense stare, the tremble of anticipation, the apparent joy with every bounce, all in pursuit of inedible prey that tastes like the backyard. Dogs are far from the only animals that devote considerable time and energy to play. Juvenile wasps wrestle with hive mates, otters toss rocks between their paws, and human…