What's that pong Hamilton?
Some say it is like a pile of dead cows, others reckon it's closer to rotten eggs.
And despite a hunt by Waikato Regional Council, Hamiltonians are no closer to knowing exactly what is causing the mystery foul smell that is wafting over suburbs.
Melville mother Esme Christensen says she first smelt it on Monday and it was so bad at times on Wednesday night that she couldn't stomach her dinner.
"I thought the dog found something to roll in to start with so I washed him," she said.
The stench persisted.
"I thought the cat had maybe caught something and it was under the house. Then I smelt it up at the Urlich Ave shops and I thought: 'This can't be from my house.' "
Christensen knows what silage smells like and she said it wasn't the culprit. Although there was a whiff of it among the odour on Wednesday.
She posted her observations in an online forum and the mystery deepened.
Jackie Tyler thought "a certain tree" exuding a rotting scent may have been responsible.
Jenna Fraser put it down to civic work on the drains and broadband.
Renee Werder said she thought it was a dead cat on the nearby high school field.
The Waikato Regional Council received one complaint about the odour on Tuesday night and sent a staff member on the hunt on Wednesday.
They tried all the usual suspects, such as meatworks and processing plants, but they came up clean, spokesman Stephen Ward said.
On Wednesday night a further two complaints came in and the search for the source of the stink resumed yesterday.
Ward said they found a farm in the Temple View where a wet batch of chicken manure was spread on the paddocks.
"Apparently when it's wet it can make it pongier," Ward said.
"We've been talking to the farmer about how to better manage it and in the future. He's saying he spread it on Wednesday and that would not explain the odour call on Tuesday night."
But the council was 100 per cent sure that the two Wednesday calls were connected to chicken poo.
Ward encouraged people to call the council's 0800 number (0800 800 401) and report any foul and nebulous odour in order for investigators to home in on the mystery source.
"We're keen to work with people to try to sort it out as much as we can and obviously we do not want people affected by offensive odours."