Of all the homes for a seal to enter, one managed to chase a cat into the Mount Maunganui residence of a marine biologist - who was not even around to see it.

University of Waikato researcher Phil Ross said his wife Jenn Ross' "hilarious" encounter in their lounge on Wednesday, while he was away for work, had already become a family joke.

"This was the one kind of family emergency where a marine biologist would have been useful - I missed my time to shine," Phil said.

He said his wife got up on Wednesday morning to go out and thought she heard something "barking" and something "scurrying" away as she hopped into the car.

Thinking it was just a neighbourhood dog, she headed out.

On her return, she parked in the garage and went into the house to find not a dog but a "small and very cute" New Zealand fur seal hanging out in the lounge.

The seal entered through two cat flaps before exiting out the front door. Photo /Supplied

Phil said it "had a good roam around the house", visiting a spare room and even hopping up on a couch.

He suspected the family of four's cat, Coco - known to confront dogs - might have come across the seal in the front yard and "tried to take it on" - with the seal responding in kind.

Phil said to make it into the house, the seal would have had to pass through a pet flap into the garage, and then through a second pet door into the house.

Coco the cat was 'traumatised' after being chased by the seal. Photo / Supplied

He said the family lived on Oceanbeach Rd near Omanu. To even reach the driveway, the seal would have had to clamber up a beach access and continue up the road.

"It must have been on a bit of a mission."

Phil, who works at the University of Waikato's Coastal Marine Field Station in Tauranga, said Jenn found it all "hilarious".

DoC was called and Jenn let the seal out the front door. It roamed the yard until a ranger arrived to collect it after a busy morning of seal-related callouts.

Phil said the family often saw seals on the beach this time of year, but he had never heard of one coming into someone's home.

The Ross family - Noah, Jenn, Ari and Phil. Photo / Supplied

He said it was likely a juvenile on its own after being weaned from its mother. It would have come to the beach for a rest from the storm.

"At this time, of year you can expect to see seals up on the beach and roads, and to be in unusual places.

"The message is to give them space and keep dogs away."

Their two children Noah and Ari were "stoked" with the visitor, he said.

"They thought it was pretty cool to have a seal in the house, but they don't get that this is such a strange thing to happen ... they just think it's another cool thing about living in the Bay of Plenty."

The family moved to Mount Maunganui in October 2012 for Phil's research and environmental monitoring work on the ecological impact of the Rena shipwreck on Astrolabe Reef.

Seals at Astrolabe Reef. Photo / Supplied

His career has also taken him to Antarctica - the only other place he has seen seals so far from their ocean homes.

He said dry valleys were "full of mummified seals" that had essentially been "freeze-dried", some 15 kilometres from the ocean - no one was sure why.

He said his seal visitor was released back into the harbour.

The "traumatised" cat was found hiding out on a neighbour's property.

He said Coco would not go downstairs for the rest of the day, but has since had a sniff around.

"I'm pretty happy there is no seal poo on the carpet or the couch. I am sure that would have been fairly terminal for the furniture."

'Seally' season

The Department of Conservation says that from July to September each year there is an influx in adolescent seals appearing on shores and further inland.

This is because seal pups begin to wean as their mothers prepare for new pups.

During this time they can pop up in peculiar places: "Seals can wander as far as 15 km inland, often by following rivers and streams. They can appear in unusual places, such as a paddock, roadside or an inner-city street. This is a normal occurrence from exploratory behaviour."

In Tauranga, seals have previously turned up in industrial areas and around popular walkways.

A seal pup on the Mauao Base track in August 2019. Photo / George Novak

DoC's advice was that people should never attempt to touch a seal and should stay at least 20 metres away when watching them.

DoC generally took a hands off approach but would intervene in certain circumstances such as if a seal is in immediate danger, causing a disruption or being harassed.

If concerned, call the emergency hotline: 0800 362 468.

-  Samantha Motion, NZ Herald