Historical clue formulations

• Milk sources — 2025-06-13
• Milk sources — 2024-04-18
• Things milking machines attach to — 2021-05-17
• Parts of udders — 2020-06-22
• Milk dispensers — 2018-12-10
• Milk dispensers? — 2016-08-21
• Nature's pacifiers? — 2015-03-20
• Littermates compete for them — 2014-02-07
• Parts of sows and cows — 2013-12-15
• Parts of an udder — 2008-03-03
• Milk dispensers — 2006-08-25