A DEEP growl outside Margaret McKenzie's bedroom window has her fearing a member of the big cat family is living free near her acreage property.

Ms McKenzie said in a Facebook post at the weekend she heard the sound at her Bald Knob home.

"We were woken in the early hours by a very loud cat growl right outside our bedroom," Ms McKenzie wrote.

"This was not a domestic cat.

"It was much louder and deeper and sounded like a member of the big cat family.

"We got up and tried to see what it was but didn't manage to spot it."

She wondered if anyone else in the district had seen or heard the cat.

"Putting the spotlights on and moving around clearly chased it off," she said.

"I considered walking around the yard with a torch but quickly decided against that in case it was still in our yard."

She was sure it wasn't a possum or koala.

"This was a definite cat growl but much bigger and louder than a domestic cat."

A feral cat information sheet on the Biosecurity Queensland website says feral cats differ little in appearance from its domestic counterparts; however, when in good condition, can display increased overall muscle development.

This can be especially noticeable around the head, neck and shoulders, giving the animal a more robust appearance.

"The average body weight of male feral cats is 3-6kg, while females weigh 2-4kg," the website stated.

"Body weights vary with condition, with some extremely large specimens documented."