“Nest” is a collective noun that gets used far beyond birds — it shows up for snakes, vipers, and, in this case, toads too. Rather than referring to an actual constructed nest, it describes a group of animals sheltering together in one place, which fits toads well even though they don’t build nests the way birds do.
Toads don’t lay eggs on land or guard a built structure, but they do rely heavily on shared shelter. Burrows, loose soil, and damp hollows serve as a kind of home base, especially outside of breeding season when toads spend most of their time on land rather than in water. It’s common to find several toads occupying the same burrow system or sheltering under the same object, which is likely where the “nest” comparison comes from.
The term also loosely echoes the breeding side of toad life. While the eggs themselves are laid in long strings in water rather than in a nest, the areas around a breeding pond can get crowded enough with adult toads that “nest” doesn’t feel like too much of a stretch.
Example: “A whole nest of toads emerged from under the compost bin once we started digging.”
Related: Collective Nouns for Amphibians · What Is a Group of Toads Called?