It is important to know how to, and how not to, handle a rat.
A lot of rat behavioural problems are caused exclusively by people not knowing, or not caring about, how to handle them properly.
The first thing to be aware of is that a new rat is going to be overwhelmed and probably a bit stressed at coming to a new home. This will make them slightly more defensive than they would normally be. Also remember that you are many times his size, and rats are prey animals.
It is important to move slowly, and quietly when picking up a new rat. Loud noises and sudden movements will put a rat on edge and make him more scared.
If your new rat is used to being handled already, such as if he came from a good breeder or rescue as opposed to a pet shop, he may come to you willingly. But if you've got a rat who is nervous, or has not been picked up before, patience and confidence are the keys.
Rats should be grasped around the shoulders, just behind their front legs, and the other hand should support their bum.
Always hold a rat close to your body, do not hold them at arms length away from you. You'd be amazed at the amount of people I've seen do this who then wonder why the rat is struggling and feels insecure. A rat needs to feel secure when it is picked up, so hold him close to your chest so he feels a bit enclosed. Rats like to have 'walls' around them and feel like they're huddled inside something, they do not generally like to be exposed as, in the wild, this would leave them vulnerable to predators.
If the rat is very scared, it can sometimes be helpful to also cover his eyes so he is in a dark, enclosed space.
Always aim to sit down when handling a nervous rat. Scared rats are capable of leaping out of a person's arms far quicker than we can stop them, and you want to ensure that, if this does happen, he has as little distance as possible to fall.
Do not pick a rat up by it's tail.
This is not only painful (can you imagine someone dangling you in the air by the end of your spine?!) but it can cause the skin to slip off the tail, leaving just exposed bone. This is called a degloving injury, and is more common than you'd think. Rats are not designed to dangle by their tail.
In an absolute emergency, such as a rat about to escape down a hole or behind a fridge forever, you can grab the tail but only ever the base where it is thicker. Do not try to pull on, or pick a rat up by, the tip; it will deglove.
If you have a nervous rat and you want him to get used to being with you, there is a very efficient technique known as 'forced socialisation' that I often use myself with good results.
Forced socialisation works on the idea that rats can only sustain their fear of a situation for 20 minutes.
After this, they learn to accept and tolerate whatever is worrying them. We can use this to our advantage by handling nervous rats in 20 minute installments. It is basically a form of desensitization.
The rat will likely act very scared initially, but will eventually begin to calm down and accept it's situation. When 20 minutes are up, put the rat back into it's cage and leave it alone for a while, then get it out and handle it again for another 20 minutes.
The rat will remember that the last time this happened, it could not escape its situation, but nothing bad happened. As a result, it will be slightly less worried the second time around. You will need to do this reguarly, and you will see a gradual improvement in your rat's behaviour.
Remember, during a 'forced socialisation' session, do not take your hand off the rat. The rat must be in contact with you at all times, either stroking him or holding him. He needs to learn that you are not a threat and that your contact is not anything to worry about, and he needs to come to view your touch as a normal part of his day.
Some people prefer a 'softly softly' approach with nervous rats, i.e, spending weeks or even months sitting at the cage door with a treat, waiting for the rat to come to them of its own accord.
I have to admit that I have never seen this method yield much success.
While it may work on some other small furries, its generally not all that useful for rats. In my experience, rats that are allowed to continue to be fearful will do so. And if they are too scared to come to you for that treat, and remain so, you're not going to get anywhere; for very nervous rats, a treat is not a big enough incentive to go against their instincts as a prey animal. The rat will just learn to hide up when you're there, and wait for you to go away. They're not actually interacting with you, or learning what you're all about. Nervous rats will always practise avoidance first, meaning that a lot of them will never make the 'leap' to interact with you and realise you're not all bad.
For me, picking up the rat, and putting him on my lap, and sitting with him is a far better way to show him that he can be in my presence without anything bad happening. And I've had many good results with this method, including rats who had previously had the 'softly softly' approach used on them for months with no sign of improvement, but who came out of their shell in less than a week using forced socialisation.
One thing I need to touch on here is confidence.
Over the years, one thing I've observed over and over is how much better rats respond to confident handlers, and how poorly they respond to nervous ones.
Many times when I get a call from a member of the public about a timid or difficult to handle rat, I'll get them to pick the rat up and put it in the carrier for me, as this gives me an idea of their handling methods. More often than not, what I see is someone darting their hand in and out nervously, or barely touching the rat before pulling away.
This makes nervous rats worse.
I came back again to understanding the rat as a prey animal, for whom sharp, fleeting movements, especially if coupled with squealing and giggling, is going to prove worrying.
In most cases, rats are far less nervous when someone just pops their hand in and picks them right up with confidence. They are smart enough to know who is confident and who isn't, and nervousness from the owner will affect the rat. Again, they are prey animals; if they think you are nervous and flighty, they will assume there is a reason for them to be, too.
Be firm, confident, yet gentle. Caution is never a bad thing and I use it with any rat I don't know. But if you actually fear your rat, you are unlikely to be able to make progress until you deal with that. It is always sad when I see owners who are blatantly terrified of their rats when the rats have never actually bitten or harmed them; its simply the owner's paranoia that they might bite.
Now this all applies mainly to rats who are not actually aggressive, just nervous, not used to handling, and struggly/avoidant. If we're talking about a rat who has a history of biting humans, or is showing obvious aggressive body language, of course it is not advised to plonk your hand in and grab them; you'll probably get bitten.
This is where a good understanding of rat body language is useful. I can tell by looking at a new rat's language whether he is being difficult because he's scared, or because he's pumped full of hormones and wants to rip my hand open; both would require a different approach. For more information on aggression in rats, please click here.