Cockroach

The cockroach is a bug in the introduced in. They are small, brown insects and are generally regarded as being disgusting, most notably by Blathers, the curator of the museum. Due to their constant availability and negative connotations with filth, they are worth only 5 Bells, making them the least valuable bug in the.

While they are not catchable in games past, cockroaches will appear inside the player's home in every game if the player does not enter it for approximately a week or longer.

One cockroach makes a cameo in, caught by Yū as a present to Ai, who screams in horror as it attaches itself to her face.

Donating to the museum
When donated to the museum, the cockroach will roam freely around the floor of the insect exhibit. If the player steps on it, a message appears telling them to refrain from doing so. In both and, Blathers is disgusted more than usual by cockroaches, even questioning why they are required to include in the museum's collection.

In
Stepping on the cockroach in the museum displays the following message:

"Your attention, please, museum patron: That cockroach was donated by  and is a valuable specimen. Please do take care not to step on it."

In
Stepping on the Cockroach in the museum displays the following message:

"Dear patrons: This is a thoughtful donation from . Please do not step on it."

Cockroaches in the player's house
Cockroaches appear in the player's houses if neglected for a week or more, scuttling on the floor and taking shelter underneath furniture. Depending on how long the player has been absent, more cockroaches will appear. Villagers that may come to visit the player's home will leave immediately upon seeing a cockroach, while expressing disgust at the cockroach (with the exception of lazy villagers in, who will not express disgust at cockroaches, and leave for other reasons, such as not dressing up for a "cockroach party").

They cannot be caught and must be killed by stepping over them. Upon squishing a cockroach, a small ghost floats into the air and disappears. In, , and , once all the cockroaches have been squished, the player does a victory cheer similar to the one displayed when a home loan is paid off.

Cockroaches in the player's house can be prevented in and  by enacting the Keep Town Beautiful/Beautiful Island ordinance respectively.

In, when visiting someone else in multiplayer, the player may step over the cockroaches in that host's house.

Real-world information
The American cockroach, also known as the Palmetto bug or waterbug, particularly in the southern United States, is the largest species of common cockroach, and is often considered a pest. It is native to the Southern United States and common in tropical climates. Human activity has extended the insect's range of habitation. Specimens have been observed in eastern North American cities as far north as New York City, Toronto, and Montreal, though its intolerance to cold restricts it to human habitations. Global shipping has transplanted the insects to world ports including Tenerife (Spain), Southern Spain, Greece, Taiwan, and Cape Town and Durban, South Africa.

The insect is believed to have originated in Africa, but had become established in the southern United States by the time that it was given its name.