It brings us at Inverse great joy to wish you a happy World Penguin Day! What’s that you say? “What’s World Penguin Day?” We’re so happy you asked.

Unlike other holidays which dates don’t coincide with any actual event — we’re looking at you, Earth Day — World Penguin Day marks Antarctic penguins’ annual march to their ancestral breeding grounds as autumn turns to winter in the Southern Hemisphere. This migration, in which Antarctic penguins of breeding age travel inland from their usual sea habitat, was featured in the 2005 documentary March of the Penguins, which helped cement the resiliency of emperor penguins in the minds of the public.

Sure, these lil dudes are cute as heck, but they’re also impressive survivors. When male and female penguins meet at their breeding grounds to do the deed and produce a single egg per pair, the mates form a strong bond as they collaborate to care for the egg and then the chick once it hatches. These pairs endure brutally cold temperatures and long journeys back and forth to the water to bring back food. The males live for months off their fat supply, losing up to 50 percent of their body weight over four months.

So in honor of these flightless birds on their special day, we’ve rounded up five Inverse stories that show just how awesome they are.

Penguin parents can't stop feeding their large adult sons

5. Penguin Parents Have Trouble Getting Their Big Boys to Feed Themselves

We all know that person who’s just a little too old to live in their parents’ house. Well, it turns out penguins have the same problem too. Penguins will feed their offspring long after the chicks are mature enough to fish. So just like adolescence extends long beyond the teenage years for some humans, apparently it does for penguins too.

Two male penguins fight in this viral video.

4. Penguins Can Be Home Wreckers

A National Geographic video broke penguin-lovers’ hearts in November 2016, as viewers saw a male penguin get his ass kicked by the male that had made a cuckold of him. In short, a male arrived at his nest to see his mate with another male. The two fought, and he lost. Of course, the loser may have very well been the intruder. Either way, this greatly complicated the popular narrative that we hear about penguins mating for life.

Tubby emperor penguins may be well-insulated, but they fall over much more easily.

3. Fat Penguins Are Less Stable, but They’re Just as Cute

In a study of emperor penguins, researchers found that fatter emperor penguins fell over much more easily than their thinner peers. To do this, they put the penguins on a treadmill before and after a crash diet. The researchers found that there was a clear advantage in balance after the diet. Why does this matter? Prior to the penguins’ migration, they’ve fattened up for the long, cold winter ahead of them. So this experiment simulated the real struggle of being a fat emperor penguin.

2. Penguins Can Be Dicks

It’s with great caution that we apply human standards of relationships and behavior to animals. After all, our brains and evolutionary histories are so much different from penguins. But when we see one penguin smacking another penguin in the head, it’s hard to not draw a comparison to America’s Funniest Home Videos or Candid Camera.

These guys are pretty stoked on their polar bear-free continent.

1. Penguins Wouldn’t Survive in the North Pole

We all know — or should know — that there are no penguins on the North Pole and no polar bears on the South Pole. For penguins, that’s a very good thing. But we also know that there used to be an Arctic penguin, and there may have even been an Antarctic polar bear. Due to the slow pace of evolution, though, it’s unlikely that we’ll ever see polar bears and penguins in the same place again.

So on this World Penguin Day, take a moment to appreciate how freaking awesome penguins are.

Photos via  Godfrey Merlen, Galapagos National Park, National Geographic/Giphy, Junko Kimura/Getty, Christopher Michel / Flickr, Flickr / mfurbo