A flourishing colony of flying foxes at Figtree is driving some businesses and residents batty.
It is estimated that tens of thousands of grey-headed flying foxes have turned a patch of bushland just north of the freeway exit into their summer home.
"The smell is overwhelming and they gather at dusk in numbers that completely blacken the sky overhead," said Chris Caroutas from Figtree Cellars.
WIRES bat co-ordinator Sandra Leonard has called for patience, assuring people the flying foxes are crucial to forest regeneration and will move on once the bush food runs out.
But Mr Caroutas said numbers had been steadily increasing each year and so had the stench.
"Customers are constantly commenting on the smell, which is not good if that's the first thing they notice when they get out of their cars," he said.
It has been likened to cat urine, marijuana and lantana.
Hakan Karama from Star Kebab House described the bats as "annoying and smelly".
"Customers are always complaining and it seems worse when it rains," he said.
Juliette Fox, an assistant at Pet Barn, said the squealing and flapping did not bother her.
"Their numbers have definitely increased but that's probably because they have been displaced from their natural habitat," she said.
Nearby resident Con Stefanou from London Drive estimates the bats have multiplied 10-fold over the past few years and believes such numbers are unhygienic.
"We see them every night from our verandah and the smell, with the right wind, can be very strong," he said.
"They used to get into my fruit trees to such an extent that I ended up cutting them down.
"There are a few of us along here who would like something to be done before the problem gets any worse," he said.
WIRES has been monitoring the colony since it appeared about three years ago.
"Flying foxes set up where there is a good food supply ... why they have chosen this spot which is not extensive, I have no idea," Mrs Leonard said.
It should be remembered that flying foxes were the original bush regenerators and were a protected species, she said.
Swarming in the sky at dusk was simply a routine.