It's very likely a very specific phrase created for a particular situation, perhaps by a small group of people or for a specific piece of writing. It doesn't have the widespread usage that common phrases do. For example, phrases like 'once upon a time' are known across many cultures and languages, but this isn't like that.
If 'cock' is being used in a different sense, like as a slang for something else, it would change the meaning entirely. But generally, if we take it literally, it might be a humorous or interesting anecdote about an irresistible encounter with a rooster. For example, a story where a person is constantly drawn to watch a particularly magnificent rooster in a coop.
It could be that the cock stories have elements like unexpected plot twists or very engaging characters that make them hard to resist. Maybe the way they're told is just really compelling.
I'm not sure specifically which 'cock cage mother story' you are referring to. There could be many fictional or even some very specific local or personal stories with this name. It might be a very unique or made - up tale that needs more context to be fully explained.
They can resist by being mentally strong. They should not show fear to the bully. For example, they can keep their calm and try to outwit the bully with their words.