“Knab” is one of the most obscure entries on any list of animal collective nouns, and we’ll say it upfront: its exact origin isn’t well documented anywhere we could verify. It shows up in scattered lists of toad group terms alongside more familiar words like “knot” and “lump,” but the historical trail behind it is thin.
One clue worth mentioning: “knab” (sometimes spelled “nab”) is an old, mostly dialect word once used to mean to nibble, gnaw, or seize something in small bites. If that’s the root, it may be a nod to toads’ feeding habits — they’re opportunistic eaters that snap up insects, slugs, and worms with quick, precise strikes of the tongue, one small bite at a time.
Whatever its exact history, “a knab of toads” has earned its place in the informal tradition of quirky, easy-to-love collective nouns — the same tradition that gave us “a murder of crows” and “a parliament of owls.” Sometimes a word survives not because its origin is airtight, but because it’s fun to say and easy to picture.
Example: “A knab of toads had taken up residence under the greenhouse floorboards.”
Related: Collective Nouns for Amphibians · What Is a Group of Toads Called?