From Computerworld’s “Q&A: A lost interview with ENIAC co-inventor J. Presper Eckert“:
What’s the zaniest thing you did while developing ENIAC?
The mouse cage was pretty funny. We knew mice would eat the insulation off the wires, so we got samples of all the wires that were available and put them in a cage with a bunch of mice to see which insulation they did not like. We only used wire that passed the mouse test.