People who see turtle hatchlings in Perth's metropolitan area are being warned not to touch them and protect the tiny animals from household pets.

Department of Parks and Wildlife (DPAW) officer Matt Swan said the hatchlings were starting to move from sandy nests, where they were deposited as eggs by their mother, to wetlands as spring approached.

Most hatchlings have a shell the size of a 20 cent piece.

"We have been contacted by a number of concerned people who have spotted the oblong hatchlings and feared they may be in danger," he said.

"If the turtles are in a safe area, we are strongly urging people to refrain from handling or disturbing them in the wild."

Earlier this week, a DPAW officer found a six-centimetre oblong turtle hatchling in his backyard in the suburb of Innaloo.

Mr Swan said it was most likely headed towards Herdsman Lake.

"We suspect this turtle may have been living in or possibly rushed down a stormwater drain, and with more rain forecast we expect more hatchlings will be washed up in backyards or on beaches," he said.

Mr Swan has also reminded people turtles were protected under the Wildlife Conservation Act, and could not be collected from the wild and taken home.

He said the animals did not survive well in captivity.