So far, the biologist estimates he has reduced the flock by about 50,000, but its total girth is six or seven times that.
Mild temperatures haven't helped
Usually the birds come in for the fall and winter, and migrate back north to multiply. This year, mild temperatures didn't stir nature's call to move, and the birds stayed and multiplied here.
The flock is larger than ever, according to Tom Broach, code enforcement officer for Danville.
The meteorologists have predicted a harsh winter, and that will mean more success for the eradication program.
When the birds have plenty to eat, they will ignore the baited bread, but with snow on the ground and a scarce food supply, the flocks will gobble up the bait.
It may seem cruel, but not to those who deal with the bird chatter and defecation.
Patterson's son says he has to clean his car every couple of days. On Sunday he washed it, and by Monday evening the birds had polka-dotted it again.
They are a health hazard
Like rats and cockroaches, the birds are scavengers, eating out of the trash and preying on dead animals in the road. They are a health hazard for human beings.
The bird waste contains the fungus histoplasma. The first symptoms of infection are mild, similar to a cold or flu, but can later lead to histoplasmosis, the leading cause of blindness in Americans ages 20 to 40, according to the U.S. National Institutes for Health.
The birds also drive out song birds, Broach said.
The droppings are acidic and can cut through the clear coat on a car. Even the city vehicle that Broach drives has fallen victim.
"You can't even wax it out, the paint job is ruined."
Broach said the birds like the mature trees in Danville, and have few natural predators. Cooper Hawks are one.
"But they can only eat so many a day," Broach said.
Working to get propane cannons
Besides baiting the birds, Broach is working on getting the state to loan the city propane cannons.
The noise will scare the birds, but because the birds have, well, bird brains, the cannons have to be set off repeatedly for the flock to get the message.
Patterson has tried setting off fireworks, but says it hasn't helped much. She's ready for a cannon.
"Next ... I'm going to take a shotgun and shoot right up in the tree," she said, shaking her head in desperation.
She goes inside to get out of the cold. Above, her the birds swoop again.