It's human nature — who can ignore a helpless baby? But if that baby is a wild animal sitting in your back yard, the best way to help it probably is to leave it alone, wildlife experts say.

Many well-intentioned people can do more harm than good by trying to help baby animals that appear to be abandoned. In most cases, they are not.

A mother rabbit, for example, may visit her nest just twice a day. A baby bird on the ground may be perfectly fine. Cindy Reyes, hospital manager at the California Wildlife Center in Calabasas, Calif., says baby birds learn to fly from the ground — which makes a lot more sense than taking the first plunge from a nest high in a tree.

"If it's got all of its body feathers, maybe a little bit of fluff, but it's completely covered with feathers, that's probably a fledgling bird," she says. "The parents care for them on the ground."

However, a naked, featherless baby bird does need to be put back in the nest. Don't let a common myth mislead you: It's not true that babies will be rejected due to their smell once a human has touched them.

"Birds have a very poor sense of smell," says Kathleen Handley of the Second Chance Wildlife Center of Gaithersburg, Md. And animals wouldn't nest in our yards if they disliked human scent so much, she says.

You can use gloves or scoop the bird into a container to move it. If you can't find or reach the nest, Reyes suggests making a substitute of a plastic container lined with soft fabric or tissues. You can attach it to a tree; the birds will usually find it and care for the baby there, she says.

(Don't use a birdhouse — the birds may not find the baby, and some species don't nest in enclosed spaces.)

This may seem chancy, but it's more likely to help the animal survive in the long run.

Wildlife rehabilitators can heal injuries, but they're no substitute for animal parents because they can't teach babies how to be successful members of their own species in the wild. And when people raise an animal for a while and then decide to give it up, it often doesn't work, she says.

"(The animals are) so bonded to humans that they can't be released," she says. "It's dangerous. They end up running up to people, and they get frustrated, and they'll bite."

A dangerous animal may have to be euthanized.

It's also illegal to keep native species as pets in most places, and many animals don't tolerate captivity well as adults.

More good reason to trust in nature: Rehabilitators' permits, typically issued by various branches of government, don't allow them to keep animals permanently, only to treat them and care for them until they can be released back into their natural habitats.