A lot of people are put off by the word feral , or even the words nervous at first. A lot of people dont know the meaning of the word feral and wrongly think it always means totally wild.
Feral kittens are often born to domestic female cats that have been abandoned, and the kittens are wild because theyve never had human contact. If these kittens are handled before they reach 5/6 weeks old, they can often be as tame as any kitten born in a domestic environment.
Unfortunately, when kittens are born outside, in the wild , so to speak, they are not usually seen until they are at least 6/7 weeks old, usually older. At this age they will hiss and spit at anything and anybody, they will need to be trapped and handled with leather gloves. They will need to be kept in a kitten pen, so that they can easily be picked up. The more they are picked up, the easier it will be, and they will learn not to hiss and spit, and you will no longer need the gloves. They need to learn that you are the provider of food, and once they are relaxed on your lap, teach them to eat there, this will make them biddable.
Kittens like this learn to love their handler only, and still revert to feral instincts when faced with strangers. For this reason it is not a good idea for them to stay with a fosterer for too long, as when they move on to a new owner, much of the former fear comes out again, not usually in the form of spitefulness, but running away and hiding, and not wanting to be picked up.
Feral kittens, from my own experience, can make wonderful pets. They can be very loyal, trusting and loving to you alone. They will never go near strangers, so will never be stolen, but may get used to regular visitors to your house.
Some kittens that are born domesticated can be so badly treated in the first few weeks of their lives, that it is difficult for them to ever trust another human being. These are usually the kittens (and cats) that are labelled nervous at first They need more or less the same treatment as feral kittens, basically lots of love, lots of patience, and lots of time.
If you would consider taking on a feral kitten, or a nervous kitten, it may be possible for the Charity to lend you a kitten pen for the first few weeks.