Literally handling - by the tail!
Not too much difference though obviously the rats will go through the food quicker. Keep em fed and watered to stave off the cannibalistic dementia. THere's not a whole lot you have to plan against yet with just a pair of them - when you get to ratropolis stage - well burn that bridge when ye come to it, laddy!
They don't require a lot of attention but do need daily checking at least on the food/water. They don't smell to horribly bad and when the cage does start to put off a funk its past due to clean it. They will chew on any and everything they can - and are fond of climbing up onto the tops of the water bottles and are good at banging their way out of their cages - stronger than they look. THey can sometimes make some deadly sounding squeals when mating . . .
Over time we've managed to produce some pretty cute looking lil buggers - I won't feed off the solid black or blonde ones though - they look too hip.