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.

[Q]: Sentence1: Bryophytes occupy niches in moist habitats. 
Sentence2: Animals and plants that live in the same place and share resources form a community biome niche .
[A]: niches


[Q]: Sentence1: hunting requires seeing prey. 
Sentence2: hunting requires seeing an animal.
[A]: hunting


[Q]: Sentence1: Birds are endothermic tetrapod vertebrates. 
Sentence2: Birds and mammals are endothermic.
[A]:
Birds