What you can do if you want to make things easier for whoever watches your rats is, put each day's worth of lab blocks in a snack size ziploc, and each day's worth of veggies (seperate each meal if you feed veggies twice, like in small batches, in snack bags), and put in a few appropriate treats, (say plain cheerios, or a slice of apple, or a couple of grapes) in a snack bag, then place all of them for each day in a gallon sized ziploc bag, and label the big bag with the day it's for. That way, your care taker only has to grab a gallon bag, and give a couple treats to distract your rats while they add food to the dish, then close the cage. In each bag, also put special instructions, if any, so its all streamlined. I'd put in day one, a note saying fill water bottles. Day two, clean and refill water bottle. And so on. Clean every other day. Put a list of ABSOLUTE NO NO FOODS on that list too. Some people like to bring their own "treats", and these can be dangerous, like peanut butter, or too much sugar. Put the bags in your refrigerator in order of the days y'all will be gone. Then post a RAT RULES sign near their cage. Rules like no taking them out of their cage, or huts. Or no outside time. And leave a disposible camera near for them to take pics while they are with your rats, so both of you can look back on cute pics later. Put any supplies they may need, like a broom and dust pan, or baby wipes. Or towels in case of emergency, and of course their travel cage with vets name and number written on the top with with instructions on how to get there. But if that's not an option, and Noone you know will take care of them, call different animal hospitals about boarding them for a small fee. Or rescues near you. They can sometimes care for them for a short time. It may cost a little bit of money, or time (helping the shelter out with duties, or a small donation. But ABSOLUTELY DO NOT leave them alone.