A man engaging in vigorous sexual congress with a woman who posesses a unkempt bush can be said to be 'feeding the rat'
A man joins assorted friends for breakfast following a heavy night out:

Man: "Goodness, you should have seen the size of the badger on the bird i pulled last night, I almost lost my kebab"
Mate #1: "Did you feed the rat?"
Man: "Yeah, I managed to throw a flacid semi up her"
by bigmikey November 5, 2005
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