Young animals found alone do better without well-meaning human interference, a UK charity says.
By Alex Kirby
BBC News Online environment correspondent
The Royal Society for the Prevention of Cruelty to Animals (RSPCA) says trying to help can do more harm than good.
It says it is better to observe the animal, then call in expert help if really necessary.
Its hospitals are overwhelmed each year with animals which should have been left in the wild.
The RSPCA says infant hedgehogs made up almost half of all young mammals admitted to its wildlife hospitals in 2002, with more than 500 receiving care.
Many of the animals were perfectly healthy, but were brought in by people who feared they were in danger or had been abandoned.
But often, the society says, the mothers would have been hiding nearby, refusing to return if a human were present.
It says: "Sadly, as with many wild animals, those that are removed from their natural habitat suffer from the stress of handling and, without having learnt survival tactics, may even die following release back into the wild."
Fox cubs need to learn survival skills
Its hospitals admitted almost 1,100 young wild mammals in 2002, including deer, foxes, rabbits and badgers, as well as hedgehogs.
It says: "Hedgehogs are mainly nocturnal, so if found wandering in daylight are likely to be sick or wounded.
"In this case, the hedgehog should be taken to the nearest veterinary surgery. However, anyone who comes across a nest of infant hedgehogs should be careful not to disturb them because this may lead to the mother abandoning her young.
"It is far better for a hedgehog to be raised by its own mother."
Tim Thomas, the society's senior scientific officer, said: "Young wildlife can be very difficult to rehabilitate once removed from their natural habitat, and taking them into captivity can do more harm than good.
"No matter how hard you try, you cannot look after a young animal as well as its parents. If you find a healthy baby animal on its own and you really want to help, leave it alone."
The RSPCA says many fox cubs spend the late spring and early summer days above ground learning how to hunt and survive.
Many are therefore mistakenly thought to be orphaned when their parents are watching from a safe distance.
Nature knows best, so leave well alone
With all infant wildlife, it says, the message is to observe from afar to see if the animal is truly orphaned or in any danger.
If a healthy young animal has remained in the same place 24 hours after it was first noticed, people should call the RSPCA.
If it is in pain or needs medical help it should be taken to the nearest veterinary surgery.
Accepting the inevitable
The Royal Society for the Protection of Birds (RSPB) gives similar advice on the best way of caring for feathered waifs.
Mike Everett of the RSPB told BBC News Online: "If you find a bird old enough to have left the nest, put it somewhere safe and wait for its parents to find it.
"Taking it in means feeding it regularly throughout the daylight hours till it's full-grown, and then there's the problem of what to do with it - it will probably have identified with you by then.
"If it can't get back in the nest, it's better to let Nature take its course. It sounds cruel to write it off, but that's the way Nature is."
Images courtesy of Andrew Forsyth/RSPCA