Crashing on the bed after a hard day at work can be one of life's little luxuries — provided there isn't a cuddly trespasser in the way.

That's the situation that recently confronted a Rosslyn Park couple, whose path was blocked by a koala they suspect snuck in through the doggy door.

Fran Dias Rufino and husband Brunno had just returned to their home in Adelaide's east about 12:30am on Wednesday they were confronted by the intruder inside their bedroom.

Ms Rufino, who is from Brazil, said she was so startled by the sight of the animal clambering onto the bedside drawers that she "forgot my English" and instantly resorted to her first language, Portuguese.

"I thought, 'Oh my god, there is a koala in my bedroom', and [Brunno] was like, 'Lady, what are you doing? Why are you screaming?'," she told ABC Radio Adelaide.

"I was afraid it was a spider because she is arachnophobic."

The incident was captured on video, which shows the pair frantically attempting to shoo the creature outside.

Ms Rufino said she did not realise the koala was inside her home until she took her dinner to the bedroom and saw it on her dog's bed.

"We just arrived [home] from work and he was there, and we believe he came inside the house through the dog door," Ms Rufino said.

"We were afraid they'd get [into] a fight, so we put my dog away, and I asked Brunno to help me."

After climbing into the drawers, the koala leapt onto the bed.

"Brunno tried to hold him with some clothes and he grabbed the clothes and I called for the koala rescue and I forgot how to speak in English and I started to speak Spanish – and I don't speak Spanish," Ms Rufino said.

"I was like, 'Please help me because I have no idea what to do, help, help'."

Meanwhile, Mr Rufino was hatching his own plan.

"[I] closed all the doors and left the front door open but he didn't want to come out the house and I then I had to scare him a little bit and he was running [from] one side of the house to another," he said.

"I just kept nudging him with the blanket."

Wildlife recovery group Koala Rescue warned people not to pick up koalas if they appeared in their homes.

The group's chair Pam Head said they should instead call an expert straight away.

"[Put] a laundry basket over the koala ... and then the rescuer is in a better position to [save it]," she said. 

"Keep your distance, even if they are cute and cuddly.

"They can become stressed and they are likely to reach out."

The koala in question was eventually coaxed out the front door, but then went into the back garden and climbed up a tree.