The best thing you can get, which also is the easiest and stress free way is to go to the vet and get Stronghold.
One drop in the neck will most of the time fix the problem. Some might need a repeat after two weeks or so but other than that you won't need to do anything since the lice can't survive without it's host.

Drop 1 drop in the neck of all your rats and the lice will die off.

There are stuff you can get at the drug store but that's not as good, takes more treatments and will stress the rats as they need to get a bath more than once in a short while. 

It doesn't cost that much and is for sure the best way to go in this matter.

Do you know how much it usually costs for this kind of vet visit? I will have to pull some funds from the savings most definitely

#2 It all depends on which vet you visit and what part of the country so I sadly can't give you a good answer to that :/
I would suggest you make some calls to vets close to you and ask :)

For me it's been around anything between 200-500SEK depending on where I go (that price include Stronghold which you get from the drug store, but you need a prescription from the vet)

Alright, 200-500 is do-able. Hopefully its within that range! :P How do rats get lice anyway? Seems like they showed up overnight :( Wonder if maybe I did something that brought them in. The only new thing here is a new bag of food and I highly highly doubt they came in the food o.o

#4 I'm so terrible uneducated when it comes to lice seen as I've never had it myself but I believe the lice are, hmm trying to think of the correct term… xD
They are species specific so dog lice to rat isn't possible - rat lice to rat is. I also believe the lice can't survive without the host body so I've never fully understood how people get lice when they haven't brought anyone new into the pack.

But I do believe that if one have lice and you don't notice it they might jump between the rats before you notice it so you might see it on Kuzco but not on his pack mates even though they too most likely have it. (which is why All rats in the pack need to be treated) 

Though once again, I highly lack education in this matter so it's more my speculations on this part.

They could be lice that crawled from you onto him. If so they won't survive much longer than 24 hours; so make sure to check up on him again tomorrow to see if you're the one spreading the lice. That way you can get yourself cleansed from those horrible little bastards.

Also if one of the rats have lice, the rest of the pack will also be carrying them and will be needing treatment. The vet can subscribe you stronghold as previously stated :)

Well, This morning I woke up early to give the boys baths and scrub down their cage. And no lice in sight… o.o They have a few scabs but I think its from my boys starting to hit the hormonal stage and they've been picking at each other a bit more so I separated the 2 young ones from my old man and we will see if they clear up. There are a few white specks I saw on the fur, but unsure if its eggs. there's not a lot of them. I will give it a few days and see if Kuzco's scabs clear up or not. If they do it is probably from them fighting. If not, I will call the vet and get him seen. He hasn't been itching lately so maybe its not lice. Maybe some other bugs that crawled in the window they are right next to? Weird. And nope, no lice on the humans here either ;D

I should treat them anyway. Not fun for the rats to have lice. And yes you can wash away live lice. But the eggs are hard to wash away and will hatch sone. So its just unnecessary stress to give them bathning so often that will be needed to take away al hatched lice until they are completly free from it. 
And not healthy for there skin that will risk on getting dry. 

Dont need to cost so mutch. Lice is pretty easy to kill. This works on lice and take a few day to get home. I have tested it with good results. http://www.ratwarehouse.com/shop_detail.php?item=637&cat=11

I second Stronghold, it's really efficient. Quick and easy. Also, when you buy it, you'll get more than you need, so if it happens again, you'll have some to spare.