Historical clue formulations

• Infiltrators of a sort — 2025-06-07
• Earthworm hunters — 2024-02-06
• Earthworm trappers — 2017-05-05
• Mexican sauces — 2013-12-22
• Yard menaces — 2010-05-19
• Some spies — 2008-10-22
• Ones with shovellike forefeet — 2008-07-12
• Lawn diggers — 2008-04-29
• Some infiltrators — 2007-03-16
• Some spies — 2006-11-22
• Tunnelers — 2006-05-17
• Underground workers — 2003-05-09
• Double agents — 2002-11-07
• Double agents — 1998-11-05
• Chemistry measurements — 1997-04-30
• Infiltrators — 1996-12-26
• Tunnelers — 1996-09-21
• Yard pests — 1996-08-07
• Kim Philby and others — 1996-01-28
• Lawn pests — 1995-01-02