Pinkies come in different sizes (as all baby mice without fur are pinks and new born pinks are significantly smaller than pinks that are several days old )as do froglets. I wouldn't offer a newly metamorphed horned frogs pinks (but would use fish) but I also wouldn't offer a really large pink to a smallish froglet. You need to be able to judge the size of the pink to the froglet.

Ed