More than 40 monkeys escaped from a research facility in South Carolina on Wednesday, prompting warnings for nearby residents to secure their doors and windows. The fugitive monkeys had not been captured as of Friday morning.

Here is what we know so far:

Where exactly did the monkeys escape in South Carolina?

The primates broke loose from Alpha Genesis in Yemassee, Beaufort County in South Carolina.

The company confirmed 43 rhesus macaque primates escaped from an enclosure at one of the company’s facilities.

The Yemassee Police Department said on Thursday that traps with bait were set up and thermal imaging cameras were being used in an effort to capture the monkeys.

“Residents are strongly advised to keep doors and windows secured to prevent these animals from entering homes,” police said. “If you spot any of the escaped animals, please contact 911 immediately and refrain from approaching them.”

How did the monkeys escape the research facility?

Greg Westergaard, CEO of Alpha Genesis, told CBS News on Thursday that a caretaker inadvertently failed to secure a door at the enclosure, allowing the monkeys to roam free.

“It’s really like follow-the-leader. You see one go and the others go,” he said. “It was a group of 50 and 7 stayed behind and 43 bolted out the door.”

He told CBS News on Friday that while they have not captured any of the monkeys, they are staying close to the facility.

“They’re just being goofy monkeys jumping back and forth playing with each other,” he said. “It’s kind of like a playground situation here.”

Westergaard said the company has put out baited traps but the monkeys are not going inside them yet.

“They’re jumping down and taking the food and then jumping back up on the fence and the tree line,” he added. “They’re watching us the same way we’re watching them.”

He acknowledged that it would be a long process to get them back and that they didn’t want to chase the monkeys because that would spook them and make them run away.

“We’ve got them very close,” Westergaard said. “This is all like what we want to see.”

What kind of monkeys are they?

The monkeys that escaped are rhesus macaque primates, which have brown fur with red faces and ears. They have close-cropped hair on their heads, which accentuates their very expressive faces.

The rhesus macaques are Asian, Old World monkeys that are primarily found in Afghanistan, Pakistan, India, Southeast Asia and China.

Rhesus macaques were imported to the U.S. in the 1970s for biomedical research in laboratories, according to the New England Primate Conservancy.

Rhesus macaques are “bold, extremely curious, and adventurous monkeys” and the species is “highly adaptable to coexisting alongside humans,” the conservancy says.

The rhesus macaque’s typical diet includes roots, fruit, seeds, and bark as well as insects and small animals.

What were they using the monkeys to test?

According to its website, Alpha Gensis breeds monkeys and provides “nonhuman primate products and bio-research services” across the globe. The company’s clinical trials reportedly include research on progressive brain disorders.

Local authorities said Thursday that the escaped primates were “very young females weighing approximately 6-7 lbs” and had never been used for testing due to their age.

Alpha Genesis says its staff of veterinary technicians and animal specialists work with cynomolgous, rhesus and capuchin monkeys.

The Post and Courier newspaper reported last year that Alpha Genesis won a federal contract to oversee a colony of 3,500 rhesus monkeys on South Carolina’s Morgan Island, known as “Monkey Island.”

The U.S. Centers for Disease Control and Prevention confirmed in a statement that the monkeys were previously living on Morgan Island as “free-range monkeys” and were brought to the Alpha Genesis facility “for conditioning to be around people.”  

The facility is registered with the CDC as a nonhuman primates importer, which means it “must meet standards for the importation, quarantine, and use of NHPs,” the agency said.

The CDC added that “the risk to the public is low as long as people do not approach or come in contact” with the monkeys. 

How often do research monkeys escape?

This is not the first time primates have escaped from Alpha Genesis.

Eight years ago, 19 primates escaped from the company’s facility but were recaptured about six hours later.

CBS affiliate WCSC in Charleston at the time reported that local officials said the escapes were not infrequent but generally the monkeys return to the compound because they know that is where there is food.

“Every couple of years we’ll have one or two that get out. We have never had this many get out,” Westergaard told CBS News on Friday.

Last year in Pennsylvania, dozens of lab monkeys escaped after a truck carrying 100 of the animals crashed. All the primates were later accounted for.