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: smell is used for finding food by some animals. 
Sentence2: Food includes small rodents and birds.
[A]: food


[Q]: Sentence1: Sponges are filter feeders. 
Sentence2: Hawksbills feed primarily on filter feeders.
[A]: feeders


[Q]: Sentence1: Unit for mass is the kilogram . 
Sentence2: A balance is used for measuring the aspect of an object that is measured in kilograms.
[A]:
kilogram