When Denize arrived home the next day she was baffled to see cow pats on the back path.
"My first thought was, 'Oh, yeah, that's a cow pat'. Then I was like, 'Wait, that would involve a cow being on my back path'," Denize said.
"We live up a really, really long driveway and to get through the back path you go behind the carport, through the cars, round the corner then through a narrow alleyway between the neighbours back fence and each unit. It's a lot of effort to get all the way in there."
Another resident said on social media she lived in the same block and heard the mooing, too, but that it was too cold and dark to investigate.
The mysterious moos and cow pats have been traced back to the Mt Albert Grammar School farm herd.
The 8.1ha working farm backs onto the school, in the middle of Mt Albert and is home to a variety of livestock and a classroom centre.
A few of the cows ended up quite far from home, according to resident accounts.
A post on social media said one ended up at Rocket Park - a 10-minute walk from the farm.
MAGS Farm Manager Brett Harris confirmed 11 cows got out of the farm in the middle of the night about two weeks ago after children entering the farm from a neighbouring property left its gate open.
The cows exited through their property and Harris had to herd the animals back.
The gate has now been fixed shut as agreed by the neighbours and the school.
Harris said there hadn't been any other problems with stock escaping since a cattle stop was put in on the farm driveway about two years ago.
The mischievous herd have been attempting to find greener pastures for many years and several Mt Albert residents have shared historic accounts of cows roaming their suburb with the Weekend Herald.
Barbara Plant was at a barbecue at a neighbour's property on Alberton Rd about 15 years ago when an uninvited visitor turned up.
"We were about to cook the steaks and all of a sudden this calf came trotting down the driveway, I think it had got through a hole in the farm fence then come through another person's garden," Plant said.
Cherie Tollemache used to live in a property neighbouring the farm and said two years ago she came home to find a calf in the backyard.
"I couldn't get in touch with the farmer and we didn't know what to do. My next door neighbour was an elderly guy, he came over to help me and we sort of shooed it toward the fence with his walking stick and it sat down and rolled underneath the wire to get back. So I'm pretty sure that's how it got in," she said.
"The next time it happened it was a week later and there were 10 cows in the garden - there were cow pats everywhere.
"We managed to get in touch with the farm manager that time, because we couldn't get all of those cows back," Tollemache said.
The school said fencing and access will be among the issues looked at as part of the redevelopment of the ASB MAGS Farm.
Animal Management at Auckland Council were approached for comment but did not respond by deadline.
New Zealand police said they were not aware of the escaping cows.