Just an idle observation:
My bronze corys, bought at different times from the same store, seem to be very high strung, for corys. They practically bounce off the walls of the tank when someone comes up the stairs or walks by the tank. My peppered corys, on the other hand, would not notice if a house fell next to them, they'd just keep grazing.
Maybe bronze corys need the group factor more (I have 2), I don't know, but I definitely think corydoras paleatus (peppered) is a more laid-back fish than corydoras aenus.
Anyone else have thoughts on this?
Oh, almost forgot, I feed them TetraMin sinking tablets or Hikari sinking tablets. That, and they clean up what the others let fall (flake and occasionally freeze dried bloodworms).