Chicken lines peck at three reliable seams: crossing the road, being a little bit chicken, and eggs in all their pun-able glory. The road-crossing setup is the most famous joke skeleton in the language, so subverting it earns easy laughs.
Use them where poultry is present or implied — barbecues, farm shops, wing nights — or as low-stakes app openers where a deliberately silly start filters for people who enjoy silly.
Chicken lines thrive on the gap between the world's most famous joke setup and wherever you take it instead. The egg puns are infinite and everyone knows it, which makes restraint part of the craft: one good yolk beats a dozen.
Barbecues and wing nights supply the props; the "a little bit chicken" self-deprecation supplies the charm — admitting nerves is the most honest opener in the book. The rest of the coop lives in the animal collection, with the farmer lines next door.

