Only thing I can think of, besides the chemical idea, is that they both panicked about suddenly being "stuck"(I know you said they weren't, but they may have felt like they were since their initial instinct is to move forward to escape and they couldn't do that), and gave themselves little heart attacks :/ But thinking back on it.. I would've thought that they'd have made noises. They didn't make any noises, did they? But then again..sometimes scared animals, particularly prey animals don't make noises if they're scared.. erk, I don't know, I'm sorry.
Maybe it was just both of their times to go and they decided to hide away together? 2-3 years is unfortunately pretty common a lifespan for guinea pigs these days.
Last edited by FlickeringHope; 03-03-2012 at 12:33 AM.