toddlers

babes, babies, bantlings, infants, neonates, nestlings, newborn (or newborns), tots, tykes (also tikes), weanlings

bairns [chiefly Scottish], bambinos (or bambini), buds, chaps [Southern & Midland], chicks, children, cubs, juveniles, kids, kiddies, kiddos, moppets, sprats (also sprat), sprouts, squirts, whelps, younglings, youngsters, youths

adolescents, minors

kindergartners (also kindergarteners), preschoolers, rug rats [slang], schoolboys, schoolchildren, schoolgirls, schoolkids

brats, imps, jackanapeses, mischiefs, monkeys, rapscallions, rascals, rogues, urchins, whippersnappers

cherubs (or cherubim)

preteens, preteen-agers, subteens, teens, teenagers, teeners, teenyboppers, tweens

lads, nippers, shavers, striplings, tads

bobby-soxers, hoydens, tomboys