Generate an overlapping word between the given two sentences. When you find the overlapping words, they don't have to match exactly, e.g., "survival" and "survive" are valid overlapping words. Little words like "the" or "of" don't count! You must generate significant words which are not the stop words.

Sentence1: Some herbivores have more than one stomach. 
Sentence2: Camels are an herbivore.
herbivores

Sentence1: Insects have 2 antennae. 
Sentence2: Insects have 2 appendages to detect sound.
2

Sentence1: Frogs also have a larynx, or voice box, to make sounds. 
Sentence2: Frogs croak to alert other frogs that is their territory.

Frogs