Several naval ships of Germany were named Brummer after the blow-fly:
SMS Brummer (1884): armoured gunboat
SMS Brummer (1915): 4,400 ton Brummer-class mine-laying cruiser
German training ship Brummer (auxiliary): Auxiliary gunnery training ship, launched 29 May 1935, commissioned 8 February 1936, sunk 15 April 1940
German minelayer Brummer (minelayer): Minelayer, former Norwegian HNoMS Olav Tryggvason, captured 9 April 1940