Don't pet your bird anywhere below their neck, and only pet them gently on their head. Even if a bird's sexual organs aren't located in the areas of their back and beneath their wings, most birds still prefer being pet on the head and neck.
Try to avoid touching your parrot on the back, wings or tail. Most parrots prefer to be touched on the head. This is similar to how many parrots interact with each other in the wild. Because parrots can't reach to preen the feathers on their own heads, they often appreciate the help of a friend for this job.
Petting down the back or under the wings can lead to a sexually frustrated bird, or a bird who perceives you as a mate rather than a companion. A mated bonded bird can be hostile to others in your home, becoming jealous or possessive of you.
Physical hugging or scratching around the head is acceptable, but scratching, stroking or petting your bird around the back, rump, and hind end may cause sexual stimulation. Redirect your bird's attention towards other toys and healthy interactive play with you, the owner.
Most birds (unlike other pets) prefer being petted against their feathers. If your bird is getting relaxed and comfortable with you touching them, you can gradually start rubbing the sides of their head gently, including the skin just behind their beak and around their ears (but be careful around the eyes).
You can try to gently rub the skin just behind the its beak and the sides of its head, if it still seems relaxed and comfortable. Birds also tend to enjoy being petted around their ears. (Take care around the eyes, though.) When the bird seems relaxed and more used to petting, try petting the back of its head and neck.
When birds are in pain they will sometimes limp, hold their wing at a strange angle or something more obvious. But often they may just look at you blankly and do nothing! This is especially true for wild birds and I have seen wild birds with horrific injuries that have not shown any outward signs of pain.
There are a few places you should avoid on your bird where they won't want to be touched. Many owners will caution you against petting your bird's wings and tail since you don't want to encourage mating hormones in your animal. There can be exceptions to this but start with the head, neck, and feet.
To sum up, it's usually a good thing for your bird to come and rub its beak or face on you. It generally shows that the bird is being affectionate and recognizes you as a friend.
This will be unpleasant for your bird and birds should never be allowed to become dependent on a human (or anything else) to that degree. Even if there were no physically dangerous aspects to sharing your bed with your bird, you run the risk creating a poorly adjusted and mentally insecure parrot.
Try lightly touching and petting your bird's beak at first. Be careful not to poke its eyes, and be prepared for it to try to nip you (more of a threat from a larger bird, obviously). If your bird lets you touch its beak, try gradually moving your fingers to the skin on its face just behind the beak.
The following are indications that a bird may be sick or injured: The bird is quiet, dull, the eyes may be closed, and it has fluffed feathers (the bird looks “puffed up”). It may have an obvious wound, breathing problems, a drooping wing, or show lameness or an inability to stand.
Chances are that your bird is not trying to be aggressive, as biting is not a dominance behavior in birds. Biting among wild birds is usually only an act of self-defense, and not a "pecking order" signal, nor any type of punishment or social correction.
Life in captivity is often a death sentence for birds, who may suffer from malnutrition, an improper environment, loneliness, and the stress of confinement. Birds are meant to fly and be with others of their own kind in a natural environment. Confinement causes birds to have temper tantrums and mood swings.
Birds may feel for others (have empathy) and even console them, may have a sense of justice, may show deep affection for their partner and grieve for their loss.
While many young birds do learn to enjoy cuddling, this can actually be detrimental to their health as they mature, especially for a female bird. When parrots are young, they may live in flocks and have companions within the flock.
The best rule of thumb if you find a baby bird or any animal infant is just to leave it alone. In most cases, the parents are nearby and may be waiting for you to leave the area. Touching animals can also result in diseases passing from wildlife to humans, or vice versa.