8 Uncanny Animal Lookalikes

Coral Snakes and Milk Snakes

Here's a mnemonic that could save your life one day: "Red on yellow will kill a fellow; red on black is a friend of Jack."

Coral snakes (like the one on the left of the photo) are not aggressive but possess extremely potent venom. Milk snakes, a kind of king snake, are harmless but benefit from similar coloring to their dangerous cousins. When a nonthreatening species evolves to look like a harmful one, the phenomenon is called Batesian mimicry, named for the 19th-century English naturalist H.W. Bates.

Viceroy and monarch butterflies

Another kind of mimicry is Müllerian mimicry, named after the widely accepted theory advanced in 1878 by the German naturalist Fritz Müller. This occurs when two species both benefit one another by looking alike because they are both equally unpalatable, as is the case with viceroy (left) and monarch (right) butterflies. Usually the species share at least one common predator.

Once you learn to tell the two apart, it's really quite easy to distinguish them. Everything else about the butterflies is nearly identical except for the viceroy's slightly smaller size and telltale bold black line that runs across its lower wings.

Swallowtail caterpillars and snakes

When you share a common predator, like birds, it's good to be — or look like — a snake! The incredible spicebush swallowtail larva (left) mimics the common green snake (right) in both pattern and behavior; these clever caterpillars will raise the front of their bodies to look like a snake about to strike, and they even stick out an organ that looks like a snake tongue!

Honey bees and drone flies

Drone flies (pictured on the bottom) fool more people than you might think, especially when observed from a distance as they roam near flowers, covered in pollen. Native to Europe, the species now finds its home in North America as well, so be on the lookout for these distinguishing features: one set of wings, as opposed to the honey bee's two; short, stubby antennae; larger eyes and thinner legs. Another example of Batesian mimicry, the harmless drone fly benefits from looking like the stinging honey bee.

Glass lizards and snakes

These two slithering reptiles look awfully similar, but one of these "snakes" is not like the other! Glass lizards (like the one at the top of the photo) are also known as "glass snakes" or "jointed snakes," but they are actually legless lizards, despite how much this one looks like the Florida kingsnake pictured below it. Though they must slither around on their bellies, these tricksters have eyelids and ear openings just like any other lizard.

Flatworms and sea slugs

Flatworms (left) often mimic sea slugs (right), but the species are quite different. Flatworms lack body cavities, respiratory organs and circulatory systems — they're pretty much just flat animals with holes for food to go in and out. "Sea slugs" is a term that describes many differents kind of marine creatures including shell-less saltwater snails and nudibranchs. Nudibranchs are conspicuously colorful mollusks that can secrete toxins as a defense mechanism, so it's easy to see why flatworms might evolve to look like them.

Jumping spiders and ants

Can you tell which is a spider and which is an ant? Some species of jumping spiders can mimic ants almost identically — and sometimes even use their extra pair of legs as "antennae." In this photo, the spider is actually in the bottom right corner. While some spiders look like ants as a form of agressive mimicry (to fool them into thinking they are safe), this particular species is actually engaging in Batesian mimicry. The Crematogaster ants, like many ants, are masters at defending themselves in groups. The vulnerably small dark-footed ant-spider takes advantage of its resemblance and avoids predators that include larger spiders.

Zone-tailed hawks and turkey vultures

Zone-tailed hawks have similar plumage coloring and even a similar flight style to turkey vultures. This may be a form of aggressive mimicry, since — from afar — the predatory hawk resembles the harmless scavenger. These hawks have even been seen tagging along with kettles of vultures.