Mice too boring for you? Maybe you should try having a pet rat. They make great pets! They're sweet, smart, friendly, social, and active--as well as very entertaining--and you can learn how to take care of them through the following instructions.

[edit] Steps

2 rats of the same gender work best. Rats are best aquired from a breeder or rescuer. They have a more intimate knowledge of the rats in their care and can help you find the "right" one. Always thoroughly research any rescuers/breeders before getting a rat from them. This is often a better choice than buying a pet store rat (which are usually from "mills" and little consideration is taken for their health). If you do decide to buy from a pet store, avoid rats with the following problems: red discharge around the eyes and nose, noisy breathing, open wounds, lethargy, cloudy eyes, or runny poop. The danger of getting a rat from a pet store is that often mix-ups occur and the genders may be mixed. You may be only buying two rats initially, but a few weeks down the road you may get quite a surprise!
Find a veterinarian who has KNOWLEDGE and EXPERIENCE with rodents.
Buy a large cage with solid flooring, levels, and ramps. Wire flooring can cause bumblefoot and that is painful for your rat. The barspacing should be no more than a 1/2 inch (chicken wire can be used to seal gaps) and the bars themselves should be powder coated to avoid zinc poisoning. Rats are excellent jumpers and climbers and should be able to execute their acrobatics in their cage.
Wood chips and shavings (Pine and Cedar) are dusty and contain oils that could cause respiratory infections, among other things, in rats. Use a hemp or cloth bedding. Be sure the cloth isn't frayed however as they could cause your rats harm. Another good alternative to shavings is Carefresh, a reclaimed cellulose formula.
Spend time with your rat. The more attention you give, the more bonded, active, healthy, and friendly your rat will be. A single rat is a lonely rat and this can cause behavioral issues. Unless your rat is aggressive, they are best not left alone. It is advisable to get the rats from the same place at the same time, so as to not have to worry about quarantining them or possible introduction problems. Rat introductions can also get a little ugly especially with territorial male rats. A good spot for introductions is a big box or a bath tub.
The staple diet of your rat should consist of lab blocks. The rest should be supplemented with fresh and frozen fruits, veggies, cooked beans, seeds etc. Avoid giving citrus juices to male rats, as a chemical in the peel (which is usually in commercial citrus juices) binds with a protein in their kidneys, and causes cancer. Fresh citrus is fine, as long as you remove any skin and pith (the white stuff) before feeding male rats. Females do not have this problem. If you must purchase commercial rat food be aware that the corn and alfalfa pellets are undigestable and small seeds will likely go uneaten. Many vets recommend Reggie Rat and Teklad.
Make food readily available. Rats will stop eating when they are full. Buying premade "rat mixes" isn't necessarily the best choice as some rats will eat only the pieces they enjoy and leave the rest. Some recommend buying "lab blocks" which are "nutritionally complete" and supplementing with fresh fruits, veggies, dry bread, yogurt. Rats may become bored eating the same thing every single meal, and can stop eating. Dog food made for Seniors (which has a lower fat content) can be a good supplement to their regular diet.
When buying rat food ensure that it is not just seeds and nuts! These mixes contain too much protein and fat for rats. Also ensure that corn is not the number one ingredient in the mix as too much may contribute to cancer. Instead of searching for a good rat mix, you can choose to make a homemade mix such as Suebee's (see external links).
Clean their cage often! Daily "spot-checks" help maintain a clean cage, and at least weekly cleanings will ensure healthy rats. Harsh chemicals, like bleach, can harm their sensitive respiratory systems. A vinegar solution, or retail pet-friendly product like Nil-Odor work well.
Do not leave your rats exposed to extreme temperature changes or drafts.

[edit] Tips

Rats love other rats! A pair or even group of same-sex rats will result in happier, healthier pets, while a lone rat may become bored, timid, clingy, or suffer depression and neurological problems.
Males can easily be differentiated from females by the presence of their large testicles. They are also larger in size.
A happy and contented rat will "brux" by chipping their teeth together. Sometimes their eyes bug out a little when they are really bruxing hard, but don't worry! This is just like a cat purring, it means your rat loves you.
Rats love treats. Fresh veggies and fruits, healthy cereals, and baby foods are some of their favorites. Rats don't tolerate lactose well.
Giving your rats ropes to climb, mazes to solve and things to chew will make them very happy.
Rats don't sleep all through the night or all through the day. They are neither nocturnal nor diurnal. Instead they sleep about an hour at a time, constantly going to sleep and waking back up agian. So essentially they are active at all times of the day with naps in between. Also they can sometimes be quite noisy, but usually at a tolerable level. You may prefer to keep them in a room separate from your bedroom. If you do choose to keep them in your bedroom, it is handy to keep a basket of rolled up socks nearby to throw at the cage if they get too noisy (this may sound mean, but it works really well).
Find an exotics vet that specializes in small mammals. They're worth their weight in gold. Keep their number on hand in case of emergency.
Talk to your rats. They like it.
Make food a puzzle, wrap up a snack in some paper towels or cardboard, for example.
Don't overdo protein in their diet, it can cause (among other things) a nasty rash.
Give your rat something to chew on, such as a toilet paper roll. They love using the chewed up pieces in their nest.
Female rats tend to be more active. If you want your rat to sit on your lap for petting sessions, get a male.
A good method of cleaning cages to remove the smell is to use a spray bottle of white vinegar and a spray bottle of peroxide. First spray the vinegar on the cage, then the peroxide, and wipe clean with a paper towel. This will remove odor and disinfect the cage for cheap.
You can quickly train your rat to use a litter pan. Place the pan in the corner they most often use and put in a small amount of the soiled bedding. If the rest of the cage is clean, they will pick up on where the toilet smelling area is. Use a different litter in the pan than what is in the cage to help them differentiate the area. This will only work for their solid waste, as they use urine for communication and won't confine where they pee. Females tend to litter train better than males.
Training a rat to come on command is easy and useful. They can be trained with positive reinforcement with food rewards. Common food rewards are rice crispies, sunflower seeds, cream cheese on finger, ect. This can be used to find missing rats and is something an owner should take the time to do.
It is a misconception that rats get bumble foot from wire floors and shelves. It actually comes from walking in urine and feces all day.
Rats like to hide. So put like a small box in your rats cage so it can sleep and hide there.
Rats are prone to mites and skin parasites. If your rat starts to look mangy or you can see tiny orange specs moving on him, he has mites. Fortunately this is easily fixed with a spot-on flea treatment meant for kittens (eg Frontline).

[edit] Warnings

Never keep male and female rats together in the same cage unless the males are neutered. The females will become pregnant very quickly, and you will end up with more rats than you ever wished for.
Never pick your rat up by the tail! Always use two hands to pick them up. Grasp them around the middle with one hand and use the other hand to scoop up their backside.
Do not feed your rat sticky foods (peanut butter, caramels, marshmallows, etc.) or carbonated drinks in large amounts. They cannot regurgitate so they can choke and are not able to release gas buildup.
Rats chew on everything! Keep cords, shoes, clothing and other things you don't want chewed on out of their way.
Rats are quite clever and can get into spaces you wouldn't think they'd be able to. Keep a close eye on them when they're out. They like to jump off things, too.
Rats have quick and severe reactions to sugar. They will become hyper should you give it to them.
Rats can get sick often and are expensive to treat. They can cost a lot of money to keep, so be prepared to spend it.
Rats have a bad rep. People will act really strange, mean, degrading and grossed-out when you mention you have a rat. Be ready for this.
Rats can be very timid, or aggressive when you first bring them home (this is especially true for pet-store rats). Be patient when handling them.
Rats tend to see other animals as either predators or food, and they can and will kill smaller rodents.
Be careful with cats and dogs. A housecat may investigate a rat as an interesting new family member, but a rat will see a cat as what it is: a predator. The rat may very well decide that the best defense is a good offense.
Some rats wil use a running wheel, but most will just ignore a wheel. Also, many rat owners argue that the wheel is damaging to the rat's back. Unlike hamsters, a rat's spine is not designed to bend that way and it could cause problems espessially if the wheel is too small. Most people just let their rats run around their rooms for excercise anyway. If your rat does use a running wheel, avoid wheels made with wire as their feet can easily become tangled in them. Solid plastic wheels are safer and can provide extra exercise.
If you have a wire cage, Make sure your rat, in its cage, is not walking around on the wires. Always have the floor of the cage be bedding. Placing bedding beneath the wires is unacceptable; this walking on the wires may cause your rat to develop Bumblefoot, creating serious bumps and bruises on their feet from walking on just wire all the time; imagine if you had to!