The scientific name of this species is Naryciodes posticalis, and it can be found only in Japan. It belongs to the Limacodidae family of moths, which are commonly known as slug moths, because their caterpillars often have a gelatinous, slug-like appearance. That name seems a little ironic in this case, because Naryciodes posticalis actually mimics a snail.

Above: Naryciodes posticalis

Each caterpillar has a bulge in the center of its body, with colorful markings that form three concentric layers on its back. Those features mimic the appearance of a snail shell, which might help to deter predators. The caterpillar is also equipped with two short, stubby appendages that resemble eyestalks, but they're actually located at the back of its body.

Above: this photo shows the underside of the caterpillar's body, with its mouth slightly visible on the right

According to this article (translated from Japanese):

Even during the final instar, the caterpillars' body length remains quite small—approximately 8 mm—and because their morphology resembles that of a snail, I believe that they are often overlooked. Since their host plants are abundant along mountain streams and similar areas within the Kanto region, the larvae are most frequently discovered in such environments.

Above: a close-up of the caterpillar's head

Despite my best efforts, I couldn't find any other information about these strange little creatures, and I get the sense that the entire genus is still poorly-studied.

Sources & More Info:

iNaturalist: Naryciodes posticalis

Kawasaki Organization for Nature Research and Conservation: A Record of Naryciodes posticalis in Ikuta Ryokuchi Park (PDF)

Zootaxa: A New Species of Naryciodes from Korea

Rolled-leaf orbweaver, Poltys cf. idae, Araneidae

Photographed in Malaysia by Nicky Bay // Website // Facebook

There was a pause.

Then the human said, "That's the worst thing you've ever said."

"Don't worry about it."

"I think I have to, now."

"No, because - well - you have a species of spider which pretends to be an ant, correct? It's not capable of understanding the fact that it's mimicking an ant, but it instinctually mimics an ant in order to deter predators."

"Sure?"

"Humans produce a vff to mimic varths, predators only perceptible through vffsense. The organisms that would like to feed on you are terrified of varths, and so they leave you alone. You aren't aware you do it, you don't have the capacity to understand you're doing it, but you evolved to instinctually do it to deter predators you can't see."

There was a pause.

Then the human said in a very soft and thoughtful voice, "And are there varths on Earth?"

I did not know that the brown wasp mantidfly (Climaciella brunnea), which mimics Polistes paper wasps, can come in various morphs to mimic different species within Polistes (thanks @humanbyweight) - possibly P. metricus here! 😍

Ant Mimic Jumping Spider (Orsima Ichneumon), family Salticidae, Malaysia

The Criorhina ranunculi is a large and very convincing bumblebee mimic. Its dense, shaggy coat and somewhat rounded shape make it easy to mistake at first glance for a small bumblebee, but its hovering flight and large fly-like eyes reveal that it is in fact a hoverfly.

It appears in early spring and is often seen visiting flowering willow, where it feeds on nectar and pollen. The flight period is short, and encounters with the species are therefore easy to miss.

The larvae develop in decaying wood inside rot holes in mature broad-leaved trees, which means the species is closely associated with older woodland and traditional landscapes where such trees are allowed to remain.

Although the species occurs across much of Europe, it has long been considered rare in Sweden and is strongly linked to habitats rich in old hollow trees. In Värmland it has historically been very seldom recorded. The individual shown in these photographs, taken in spring 2025 while visiting flowering willow, was the first I have ever observed here.

another ant mimic jumping spider from Singapore. this one might have been the most antlike out of any spider I’ve ever seen, with a little crease on its opisthosoma to look like an ant’s segmented abdomen and posterior lateral eyes set to look like an ant’s angular head!