Both sea lions and seals, along with walruses, are pinnipeds, which means “fin-footed” in Latin. All pinnipeds divide their time between the beach and the ocean. Sea lions are a part of the Otariidae family, which probably descended from a bear-like ancestor; seals are a part of the Phocidae family, whose descendants were more of the weasel type. Here’s what this actually means, in terms of the differences between them:

FEET: Seals have small and stubby flipper-feet that are covered with a thin layer of webbing. Each of their small toes has a little claw on it. Sea lions have much longer, more elegant-looking flippers, and they’re mostly covered with skin.

EARS: Sea lions have small flaps for ears; seals have no external ears at all, just little holes on each side of their head.

NOISINESS: Sea lions are noisy! They love to bark and bellow and growl and roar. Seals are much quieter, usually vocalizing in softer moans and grunts.

MOBILITY: Sea lions can “walk” on land by rotating their hind flippers forwards and underneath their bodies, allowing them to support themselves on all four feet. Seals do not have this special flipper joint, so they’re limited to belly flopping/caterpillaring around, like this:

In the water, seals swim by moving their back flippers side to side, like a fish tail. Sea lions swim using their front flippers as oars, moving them in a more up-and-down motion.

SOCIABILITY: Sea lions love to hang with their friends on the beach; they congregate in squads of up to 1,500, lolling and lazing about in piles on the sand. (Walruses do this too—check out this crazy live walrus cam!) Seals are more solitary, spending most of their time alone in the water and only coming to land once a year to mate.

Here are some more fun pinniped facts, because why not:

• Walruses are the largest pinnipeds, with some males weighing up to 3,000 pounds. They have mouths that act as a vacuum and suck up shellfish from the ocean floor. They also have air sacs in their necks that can inflate and allow them to float, like built-in life vests.
• Sea lions can swim at speeds of up to 25-30 miles per hour. Seals can swim up to 23 miles per hour.
• You can tell a sea lion’s age by counting the layers in his or her teeth, like a tree trunk. The average lifespan is 20 years, though some can live into their 30s.
• Both sea lions and seals have a polygynous mating system, which means there are multiple females per male. A dominant male seal will usually have three to eight females in his clan; the average male sea lion will have ten.
• Seals can sleep underwater! They also can slow their heartbeat and hold their breath for long periods of time in order to conserve oxygen.

So…which pinniped are you? (I’m definitely a walrus.)

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In classic biology taxonomy, all insects belong to a class called Insecta: six-legged organisms with three-part bodies, jointed legs, two antennae, and compound eyes (visual organs made up of many visual units clustered together, all with their own corneas and lenses). Insecta falls within the phylum Arthropoda: cold-blooded creatures with an exoskeleton and no backbone. Your classic insects include bees, mosquitoes, butterflies, and ants—all of which fall into a variety of orders/families/genuses/species within the Insecta category.

One of those orders is called Hempitera, and it’s where the bugs live. Bugs are types of insects with certain defining characteristics: 1) They have a mouth shaped like a straw, called a stylet, that’s used to suck up juices from plants or blood from other insects or animals. 2) They have no teeth. 3) They have some weird stuff going on with their wings: their front wings are thickened and colored where they attach to the body and taper out towards the back end of the wing, and their hind wings are usually clear and tucked under the front wings. Some example of true bugs include beetles, stink bugs, and cicadas.

If you’re paying attention, you’ll notice that there’s been no mention of spiders, and that’s because…spiders aren’t insects! Spiders, ticks, mites, and scorpions all belong to a class called Arachnida, a separate class from Insecta within the Arthropoda phylum. Arachnids have eight legs instead of six, two-part bodies instead of three, and simple eyesinstead of compound eyes. They also have different dining rituals: to eat, they inject digestive fluids into their prey before sucking up the liquefied remains.

So, in summary: All bugs are insects. All insects aren’t bugs. And arachnids are their own separate category, with table manners that I’m looking to for #inspiration this holiday season. Bon appétit!

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And yet: we’re here, in 2018, and we still don’t know the difference. That’s about to change. Let’s get into it!

Habitat: Crocodiles have a special gland in their tongues that can expel a large amount of salt, so they usually reside in saltwater habitats (such as mangroves and estuaries). Alligators don’t have this gland, so you’ll usually find them in freshwater.

Jaws: Alligators have wide, U-shaped snouts; crocodiles have pointier, V-shaped snouts.

Teeth: When a crocodile’s mouth is closed, the fourth tooth on the lower jaw sticks out above the top lip—but when an alligator does the same, all of its teeth are covered. Also: alligators’ upper jaws are wider than their lower jaws, which means that if they gave you a smile, you’d only see the top row of teeth. Crocodiles, on the other hand, have a toothier grin; their jaws are about the same size as each other, and when their mouths are shut, their teeth interlock.

Skin: Both alligators and crocodiles have small, pit-like marks in their skin called integumentary sense organs, which act as motion detectors and allow them to feel for prey in muddy water. These organs, which look like small dots, are only on the alligator’s jaw—but they cover the entirety of a crocodile’s body.

Limbs: As discovered this year by researchers in Japan, alligators tend to have shorter humerus bones in their arms (or forelimbs) and shorter femurs in their legs (or hind limbs). This gives them a different gait than crocodiles; smaller crocodiles have been seen to bound and gallop on land, while alligators move in a more crawl-like manner.

We could leave it at that, but in my extensive Crocodilian research, I found some of their similarities to be even more intriguing than their differences. Read on, if you dare:

• Crocodilians go through up to 8,000 teeth in their lifetime, and they can chomp through pretty much anything: a crocodilian bite can produce up to 5,000 pounds of pressure per square inch, as compared to the 100 pounds that a human jaw can generate.

• Because both alligators and crocodiles are carnivores, they have particularly powerful senses. This translates into super-sharp vision, especially at night—their vertical pupils let in more light than our round pupils—and impeccable hearing; they can even hear their young calling out from inside their eggshells. Also, they have taste buds.

• Crocodilians can swim up to 20 miles an hour; they can run up to 11 miles per hour; they can hold their breath for over an hour; and they can survive for months in between meals.

• Crocodilians don’t chew their food; instead, they’ll swallow it whole, or if it’s too large, they’ll tear it up into large pieces. What’s more, they have to juggle their prey around so that it’s positioned in such a way that when they toss it back, it slides down their throat.

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