Given a category and a set of five words, find the word from the set that does not belong (i.e. is the least relevant) with the other words in the category. Words are separated by commas.

Category: mode of transportation 
Words: bee, swim, fly, car, walk
bee

Category: emotional display 
Words: pester, fawn, suppressed, follow, woods
woods

Category: shady activities 
Words: invent, brownie, fudge, falsehood, fix

brownie