Bug

A caterpillar or small crawling insect, or a software fault. The official name is just "bug", which in everyday American English covers any small insect, but the picture usually looks like a caterpillar, the larva of a butterfly or moth; details vary by platform. People send it for a caterpillar on the plants, something crawling across the floor or a child's garden find, often next to 🌱 or 🦋.

The second reading comes from computing, where a bug is a mistake that makes a program misbehave. That sense is ordinary English, so in a chat about an app, a website or a glitch, 🐛 simply says "there's a bug".

Why is a software fault called a bug?

Engineers called faults "bugs" long before computers existed. The earliest documented technical use dates from 1875, and in 1878 Thomas Edison wrote that "bugs" was the name for the little faults and difficulties in his inventions.

The famous story comes from 1947. Engineers checking a malfunction in the Harvard Mark II, an early computer built from electrical relays, found a moth stuck in a relay, and the operators taped it into the logbook with the note "first actual case of bug being found". Grace Hopper, a computing pioneer on that team, retold the story for decades, but she did not find the moth herself. The joke worked because "bug" already meant a fault.

What does it mean when someone sends 🐛?

Around talk of an app or code, a defect; otherwise, an insect. Beside an error screenshot or "it crashes when I log in", it says "that's a bug" or "found one". In a chat about the garden, a walk or the house, it most likely means a real caterpillar or crawler.

It has no widely recognised hidden or rude meaning. If the context gives no clue, just ask.