Watch CNN’s “Morgan Spurlock Inside Man” Thursday nights at 9 p .m. ET/PT

Story highlights

From Dr. Seuss to Dr. Dolittle, life with wild animals may look like fun, but working at a zoo is no picnic

Here are some lessons best learned ahead of time

CNN  — 

Lessons from the zoo: Here are four surprising animal facts only zookeepers know.

From Dr. Seuss to Dr. Dolittle, pop culture has made life with wild animals look like a blast. But for those who work there, a day at the zoo is no picnic.

In the forthcoming episode of “Inside Man,” CNN host Morgan Spurlock becomes the latest human to weave his way within the fur and feathers, trying his hand as a zookeeper.

For those looking to follow in Spurlock’s dung-encrusted footsteps, here are a few lessons best learned ahead of time:

1. If a gorilla is pursing his (or her) lips, it’s best to direct thine eyes in another direction

As Spurlock learned in his visit to the Detroit Zoo – a facility that’s been home to animals for nearly a century – gorillas interpret direct eye contact as a threat.

“So usually you look chest high on them, or directly past them,” one experienced zookeeper told Spurlock. Otherwise, you may find yourself staring at what she said is known as “threat face.”

“They stand very rigid and very tall and then purse their lips, and really very tight.”

When giving up anywhere between 200 and 300 pounds, “threat face” doesn’t exactly put a smile on an amateur zookeeper’s own kisser.

2. If you’re working with penguins, bring your own eggs

In captivity, penguins aren’t permitted to nest atop their own eggs, for fear they’ll break. Instead, when breeding season concludes, the zoos pull the real eggs and transport them to their own incubation room and nursery. Fake eggs are put in their place, leaving the penguins to wonder why nothing has hatched.

“They’ll kind of hang out for a couple more days and then they are often completely forgotten,” a penguin handler said.

The zoo’s argument is that separating the chicks from the mother penguin serves to further grow the population. But Spurlock was uneasy about the arrangement:

“I found it a little bit concerning that the penguins were being raised in incubators away from their parents, only to live lives entirely in captivity.”

3. If you have a thing for elephants, it might be best to seek the experience elsewhere

Zoos aren’t a great place to house elephants, largely because of, well, their largeness. Elephants are meant to be moving, roaming, eating, exploring. Kept in captivity, the mammoth mammal will develop a variety of health concerns, many having to do with the feet and toes.

It’s a lesson learned by the staff in Detroit, resulting in what was likely quite a road trip.

“They would have to be cooped up inside for months at a time and we just felt that that’s wrong. We knew they were suffering,” explained Ron Kagan. “After a lot of, you know, heartache we finally said what’s best for them is to do this, and ultimately were successful and sent them to a fabulous sanctuary in California.”

After traveling from the Motor City to the Sunshine State, the elephants picked up an additional 2,000 acres through which to meander.

“Here there are no cages and no visitors … just a lot of space to roam free,” explained Spurlock. “While ‘Winky’ unfortunately passed away a few years ago, ‘Wanda’ seems to be enjoying her life away from the crowds.”

4. When it comes to food, Mother (Nature) knows best

In the Detroit Zoo, veterinarians have noticed an increase in heart disease, a condition that likely stems from a combination of factors, including diet. While zookeepers try to replicate the gorillas’ natural fare, they can only come so close.

“Well, although we’re feeding them vegetables like they would get in the wild, it’s not the same plants that they would be getting in the wild,” said Ann Duncan, chief veterinarian at the Detroit Zoo. “You’ve seen they get a lot of leaves, but I don’t think they’re getting romaine in their wild habitats.”

The altered food source, plus confinement and genetics, has yielded ailments not found in freer versions of the species.

It’s an equation that left Spurlock wondering about the existence of zoos.

“It’s pretty disappointing to hear that they are suffering from heart disease, an illness they likely wouldn’t have in the wild,” he said. “It really makes me question why we would want to keep breeding more animals in captivity who may suffer the same fate.”