Just make sure they have syrup to eat. The can runs out pretty fast. I usually refill the cans but you can also spray the syrup on the screen or even brush it on lightly with a soft paintbrush. Careful not to hurt their tongues. I feed them unitl they lose interest at least a couple of times a day until I install them. IF I don't just refil the cans, but refilling the cans means opening the package and you'll have to do that outside and knock the bees down and cover the hole with something while you fill the can. Unless you have spare cans from last year, like me. :)
Mine, lately have had a can of syrup with a piece of cloth held in a hole with a plastic ring. I pop the ring out and refill it. I used to get them with just holes poked in the can. These you can't easily refill.
If you feed them you can keep them for a week or more, but they will start building comb in the package and it will set them back and stress them out a bit. I put mine in the basement with the light off. If you listen to them you can tell with the light off they are much more calm than with the light on.