Have you ever noticed these little alien-person stickers on roads in the District and other cities? In D.C. I notice them mostly at crosswalks near the Mall. But I’ve seen them in Philadelphia, too. Who puts them there? What do they signify?

David Austin, Bethesda

Answer Man has always thought of them as robots. Some people see them as aliens, others as zombies.

In fact, says the artist who creates them, they are men made of sticks: stick men.

Or, to give them the name the artist prefers, they are stikmen. That artist goes by the moniker stikman. (He prefers not to use his real name.) He responded to questions from Answer Man via email.

Stikman estimates that he has installed about 14,000 of the figures on roads, crosswalks and sidewalks around the country, from his native Philadelphia to New York to Hollywood.

In Washington, you can see one at Third and Pennsylvania NW. Another is at Third and D streets SW. More are on Madison and Jefferson avenues, near the Mall.

Stikman explained that his initial inspiration was an old plaque he saw at a flea market that bore a figure made of sticks. That figure became his leitmotif, a tool for what he calls his “improvisational art practice of finding interesting ‘canvases’ in the urban environment.”

Recently, that has included embellishing public pay-phone kiosks. But in the beginning, in the early 1990s, stikman fashioned tiny figures — about five inches tall — from wood and other materials and positioned them in the urban landscape. They were affixed to such things as walls, utility boxes and bridge abutments.

“They are easy to miss unless you are quite observant and curious,” he wrote to Answer Man.

He realized that it might be helpful to provide clues that a tiny sculpture was nearby.

“The tarmac figures seemed like a good way to mark the territory where I had been working,” he wrote. “Sort of a ‘Bat Signal’ on the ground since that is where most people’s eyes go when they are walking.”

The tarmac figures are a riff on the basic stikman elements: bold slashes of vertical and horizontal lines.

Being on the ground meant they were at the mercy of the elements, which included being rolled over by countless steel-belted radials.

“I soon realized that the figure had become a time-based form of art,” stikman wrote. “They morphed and distorted and slowly changed as time and circumstance worked its magic on them.”

In a September 2008 article in The Post, stikman (then going by “Bob”) said he’d visited Washington that summer, checked out an exhibit at the Renwick Gallery, then installed dozens of stikmen.

“He considers himself an artistic Johnny Appleseed, spreading stikmen instead of seeds,” wrote The Post’s Stephen Lowman.

The figures are made of the same material used in road markings: tiny glass beads held in a glue substrate. That makes them durable.

I asked stikman if anyone ever encountered him in the act of laying down a figure.

“I try to avoid people when installing,” he wrote. “They make me nervous and uncomfortable and I prefer my work to have an element of illusion to make it more powerful.”

In 2015, a print by stikman was among a collection of limited-edition graffiti-inspired artworks sold by Amazon. The work depicted the artist’s iconic figure screen-printed in green across the first page of the overture to Handel’s “Messiah.”

RJ Rushmore, a curator and creator of the street-art blog vandalog.com, told Philadelphia magazine: “He is a great cult figure — and a great entree into street art. His work is immediately interesting and immediately recognizable — always different, but always the same. I never tire of it.”

As for what the figures are — aliens? robots? — and what they mean, stikman says he is comfortable with any interpretation that someone finds interesting.

“I like to observe them over years to see the changes they go through,” he wrote. “Sometimes all that is left is a small blob. I guess that maybe they signify that life is ever changing as we slowly fade from existence.”

Questions, please

Do you have a question about something you’ve seen in the Washington area? Before we all slowly fade from existence, let Answer Man try to get you an answer. Send your query to answerman@washpost.com.

Twitter: @johnkelly

For previous columns, visit washingtonpost.com/john-kelly.