In many animal families the babies are not all born the same size. The smallest and weakest newborn is called the runt. Because it is little, the runt often struggles to reach its mother’s milk when the bigger babies push in, so at first it may grow slowly and seem frail. In a large litter of pigs or puppies there may be one such newborn, and sometimes two. For a long time people believed a runt could never catch up with the rest of the family.

Farmers and scientists have since learned that this is not always true. With a warm place to rest, steady food, and a bit of extra attention, many runts grow into perfectly healthy adults — sometimes even the friendliest animals of the whole litter. Feeding a weak newborn by hand every few hours is slow, tiring work, but it often makes all the difference. What a runt needs most is simply a fair chance. This is why some people work so hard to help the weakest young survive, believing that size at birth does not decide an animal’s whole future, and that a tiny, trembling newborn today may become the strongest friend of all.

No right or wrong — close the screen and tell someone nearby what happened in this part. Can’t find anyone? Tell yourself out loud. The moment you teach it, you truly understand it.