Jenny Wren gives Peter Rabbit an idea: Peter arranges to go to school to Old Mother Nature – Peter and Jumper go to school: the cottontail rabbit, northern hare, and marsh rabbit – More of Peter's long-legged cousins: the swamp hare, arctic hare, prairie hare, antelope jack and common jack rabbit – Chatterer and Happy Jack join: the squirrel family and order of rodents – The squirrels of the trees: the red, gray, fox, kaibab and abert squirrels – Striped chipmunk and his cousins: the chipmunk, spermophiles, and flying squirrel – Johnny Chuck joins the class: the woodchuck and his ways – Whistler and Yap Yap: the whistling or hoary marmot and prairie dogs – Two queer little haymakers: the pica or cony and the mountain beaver or sewellel – Prickly Porky and Grubby Gopher: introducing the porcupine and pocket gopher – A fellow with a thousand spears: more about the porcupine – A lumberman and engineer: the beaver and his works – A worker and a robber: the muskrat and the brown or norway rat -- A trader and a handsome fellow: the cotton rat, wood or pack rat and the kangaroo rat -- Two unlike little cousins: whitefoot the wood or deer mouse and Danny meadow mouse, also called field mouse -- Danny's northern cousins, and nimbleheels: the banded and brown Lemmings and the jumping mouse -- Three little redcoats and some others: the pine mouse, red-backed mouse, rufous tree mouse, rock mouse and beach mouse -- Mice with pockets, and others: the silky and spiny pocket mice, grasshopper mouse, harvest mouse and house mouse -- Teeny Weeny and his cousin: the common or Long-tailed shrew or shrew mouse, short-tailed shrew or mole shrew and marsh or water shrew -- Four busy little miners: the common mole, brewer's or hairy-tailed mole, Oregon mole and star-nosed mole.

Flitter the bat and his family: the red bat, little brown or cave bat, big brown or house bat, silvery bat, hoary bat and big-eared bat – An independent family: the common skunk, hog-nosed or badger skunk and little spotted skunk – Digger and his cousin Glutton: the badger and wolverine or carcajou – Shadow and his family: the common or Bonaparte weasel or ermine, New York weasel, long-tailed or yellow-bellied weasel, least weasel and black-footed ferret – Two famous swimmers: Billy Mink and Little Joe Otter – Spite the marten and Pekan the fisher: the pine marten or American sable and the fisher or pennant marten – Reddy Fox joins the school: the red, black and silver foxes, gray fox, kit fox or swift, desert fox, arctic and blue foxes – Old man coyote and howler the wolf: the prairie wolf or coyote and the timber or gray wolf – Yowler and his cousin Tufty: the bay lynx or bob cat and the canada lynx or lucivee – Some big and little cat cousins: puma the panther, also called cougar and mountain lion, the Jaguar, the ocelot, and the Jaguarundi cat or eyra – Bobby Coon arrives: the raccoon and the civet or ring-tailed cat, also called coon cat and bassaris – Buster Bear nearly breaks up school: the black bear and his habits – Buster Bear's big cousins: silvertip, the grizzly bear, the Alaska or great brown bear and the polar bear – Unc' Billy and Old Mrs. Possum: the Virginia opossum, which is the only American marsupial – Lightfoot, blacktail and forkhorn: the white-tailed or Virginia deer, black-tailed deer and mule deer – Bugler, Flathorns and Wanderhoof: the elk or wapiti, moose or caribou – Thunderfoot, Fleetfoot and Longcoat: the buffalo or bison, antelope or musk-ox – Two wonderful mountain climbers: the rocky mountain sheep or bighorn and the rocky mountain goat – Piggy and Hardshell: the peccary or wild pig and the armadillo – The mammals of the sea: the sea otter, walrus, sea lions, seals and manatee or sea cow.