Historical clue formulations

• Undergoes a chemical change — 2026-04-13
• Flinches or smiles, e.g. — 2024-04-10
• Jerks, say — 2021-12-10
• Bites, in a sense — 2021-07-16
• Changes color, say — 2018-09-08
• Laughs or cries, maybe — 2016-07-12
• Does something about something — 2012-04-05
• Shows shock, e.g. — 2010-09-21
• Isn't inert — 2009-08-30
• Isn't stoic — 2008-01-03
• Does a double take, e.g. — 2002-08-19
• Isn't inert — 2000-01-20