Pomona sprayed insecticide-laced mist throughout the bedroom.
Two Puffskeins had snuck in some time ago. If fleas or similar bugs had gotten inside, they had most likely brought them in.
When Newt Scamander arrived in New York, he had to undergo an inspection after disembarking. Fortunately, his suitcase had two settings prepared, or he would never have been allowed into the country.
He then went to the bank to exchange currency for his travels in America. There, he met Jacob and Tina. While Muggle federal agents were nowhere to be seen in New York, MACUSA headquarters was there, and Tina, a "former Auror," used her lunch break to keep Second Salem under surveillance.
She could have sat down and had a proper meal in a restaurant, but she only ate a hot dog. Naturally, there was even less chance of spending several hours dining "elegantly" according to the full rules of table etiquette. Her lunch break was only that long.
Wizards did not care about Muggle Prohibition. In fact, American wizards made quite a bit of money during that period, especially from Giggle Water. As long as it was hard liquor, people would drink it. Though it made people laugh uncontrollably, Muggles would not be poisoned by it.
This "water" contained Potions ingredients, while the brandy Dumbledore had brought back contained a "natural ingredient" that made people laugh...
In short, New York's public safety might not have been particularly good, but it was still far better than Chicago's. Thus, when Scamander's animals escaped from his suitcase and caused an "explosion" in Jacob's apartment, Non-Magical people quickly believed it had been caused by a gas leak, just as people in other neighborhoods believed the destruction caused by an Obscurial had also been caused by gas leaks.
The Muggles had not formed