In real life, he's a dad and grandfather, a middle-aged tech worker who drives a Subaru and lives in the suburbs.

But under his alter ego, he's a street artist who scurries around town making anonymous guerrilla art installations, secretly attaching his sculptures to the walls of public buildings and local businesses.

He calls himself Mows510, and in a few short years and without any artistic training or experience, he's made a name for himself — not just in the Twin Cities, but around the world. His creations pop up everywhere from Bali to Iceland.

Oddly enough, his street art has attracted almost universal approval. His simple sculptures are typically left unmolested by property owners and even city workers. The main question he gets from businesses: When are we going to get our own Mows510?

Maybe it's because Mows510's art is tiny and intentionally whimsical, designed to generate surprise and delight, inherently adorable rather than edgy.

After all, it's a mouse door.

Mows510 (pronounced "mouse") makes brightly painted, three-dimensional doors about 4 by 3 inches, roughly the size of a cellphone. Each one comes complete with old-fashioned hinges, a doorknob, keyhole, welcome mat and an adjacent window glowing with a bright yellow light. Mounted at the foot of a wall, the bottom of a streetlight or the base of a utility box, they look like the entrances for the home of a cartoon mouse.

"The mouse door is inoffensive," said Mows510, who asked to keep his real identity hidden. "People who don't like street art and graffiti, they like these."

If you haven't seen a Mows510 installation around town, look down.

They're installed low to the ground in "in-between spaces" at breweries, restaurants, bagel shops, comic book shops, book stores and bike stores.

Mows510 has glued a door covered with crime tape on a curb near a police station. A door with a fire department logo was installed at a fire station. A door with an image from the children's book "Go, Dog. Go!" was placed beneath the book drop of a library. A door with a little ax sticking out of it was put at a Bad Axe Throwing venue. One at the Minnesota Opera offices had tiny, mice-sized opera posters next to it.

The doors are more than just wee and twee. They are blank slates with the potential for "communicating ideas, celebrating events, mourning loss and collaborating with other artists," wrote Mows510 in an artist's statement.

He's made doors urging people to vote, and doors that are tributes to Prince, Bob Dylan and Charles Schulz. One door expressed his sadness at the death of comic book creator Stan Lee. A rainbow-colored door became a sort of shrine expressing grief after the 2016 Orlando gay nightclub shooting. Another was an homage to the Notre Dame cathedral in Paris after it was damaged by fire.

"Sometimes when I'm doing these doors, I'm processing loss," he said.

Clever, not controversial

Mows510 lives in a northern Twin Cities suburb, but he got his start as a street artist in 2015 when he was living in Alameda, Calif.

He had long been a fan and follower of street artists worldwide, especially people such as Gregos, Invader and Cityzenkane, who make unsanctioned art pieces mounted in urban spaces. Mows510 was especially drawn to three-dimensional works attached to walls. He wondered if it was something he could do.

"I eventually just wanted to join the conversation," he said.

The trouble was Mows510 wasn't an artist.

"I did zero art my whole life," he said. "I'm crap at drawing."

So whatever he came up with would have to be fairly simple and easy to execute.

"I wanted something small, but something flat," he said.

And since he was in his mid-50s, it probably needed to be something low to the ground, something he could quickly install in a public place without drawing too much attention to himself. (Many of the European street artists he follows mount their works on walls high above the street level.)

Finally, Alameda is a pretty middle-class place, according to Mows510. Whatever form his art would take, it couldn't be too controversial.

He had rodents on his mind because of the images of three-eyed mice by street artist Neon Savage in London, and the rats depicted by pioneering graffiti and stencil street artists Blek le Rat of France and the England-based Banksy.

That led to the idea of a mouse-sized door, a simple shape that he could paint and decorate, sort of a miniature, street-level canvas.

His first door, cast out of plaster using a latex mold of a model built of clay, was attached to the base of a park bench in Alameda in November 2015.

"I was 54 years old at the time and hadn't done art since childhood," he wrote in an artist's statement. He realized that his first attempt didn't need to be great. It could evolve as iterations of the mouse door multiplied.

An early evolution was making the doors out of a more durable plastic resin using silicone molds. He attached them to walls and poles with an industrial-grade adhesive.

He put the doors up at night in "ignored spaces," such as concrete walls along a sidewalk, at the end of an abandoned loading dock or in parking ramps. He took pictures and posted them on Instagram under @mows510. (His name is a reference to the area code in the eastern part of the Bay Area.)

Almost immediately, he got feedback on Instagram from other street artists who wanted to collaborate with him or trade art pieces. Later, he discovered that a Facebook group had been created by fans to share locations of mouse door sightings. People were interacting with his doors, leaving objects nearby or taking pictures of their dogs next to his doors. He noticed how the doors were treated by maintenance workers. They would remove or paint over nearby graffiti, but they would leave the mouse doors alone.

"I was surprised at the level of attention and the kind of attention," he said.

Making it in Minneapolis

He put up around 200 doors in the Bay Area and had about 2,000 Instagram followers, many from Europe, before moving to the Twin Cities about three years ago for work. In the metro area, he's installed about 400 doors and his Instagram following has ballooned to about 12,000 people.

His reputation has grown, too. There's now a certain cachet in being chosen for a Mows510 installation. That's likely why metro area businesses started reaching out through e-mail and Instagram messages, hinting that they'd like mouse doors of their own.

Market Bar-B-Que got a bright pink mouse door after owner Anthony Polski met Mows510 at Art-A-Whirl and asked to be a part of the mouse door family.

"They make you laugh. They invoke a feeling, and I think that characteristic makes good art," Polski said.

The Butcher Salt food truck reached out to Mows510 after operators started noticing the doors appearing at local breweries. That led to the first mobile truck mouse door.

"People are really into it," said food truck manager Alec Brochhausen. "When you're branded with a mouse door, you're worth checking out."

When T-Rex Cookie Kitchen moved to Eagan this year, owner Tina Rexing made sure it brought along the Cookie Monster-themed mouse door that Mows510 had installed at T-Rex's original location on University Avenue SE. in Minneapolis.

Mows510 rarely accepts a paid commission, but he does consider suggestions for an installation.

And, as he travels around town or around the world, he's always on the lookout.

"My eyes drift to potential spots to put doors," he said.

He said a police officer once spotted him in the middle of an installation and just smiled.

"No one's challenged me and said, 'Hey, take that down and don't do that,' " he said.

But not everyone finds the mouse doors adorable.

A door that Mows510 installed at the entrance of the Target headquarters quickly disappeared despite the fact that it featured a miniature Target bull's-eye.

And one local critic made an Instagram account boasting how he had torn down several dozen of the doors.

Aside from that incident, Mows510 estimates that about 90% of the doors he installs are left in place and intact. He said he doesn't use the strongest adhesive to put up a door so it can easily popped off with a screwdriver if someone doesn't like it.

"I'm hypersensitive to negative feedback," he said.

For the whimsy

Collaborating with other artists is a big part of what Mows510 does. He estimates he's sent about 1,000 unpainted doors to other people to create their own designs.

"It's kind of like Johnny Appleseed," he said. "I send them out with no obligation."

As a result, mouse doors have made appearances on skateboard decks, at a nature preserve in South Africa, in an alley in Australia and on every continent except Antarctica.

Once Mows510 was going to place a door at the Maya Cuisine restaurant on Central Avenue NE. in Minneapolis. He found that another artist he was working with had installed a door there.

"My brand is the little door," he said, but he doesn't mind other people working in the same space. He readily shares instructions on how to make the doors.

"Making is cool. I hope other people make stuff," he said.

On his website, ­mows510.bigcartel. com, he sells seven versions of painted doors, $30 for a "classic red door," $125 and up for more elaborate designs.

But he's not making little doors to make big money. He gives unpainted doors to other artists for free. He doesn't ask for payment when he installs a door at a business. And he leaves tiny business card-sized versions of his door for people to find in cafes as part of the Free Art Friday movement.

"I haven't tried to turn it into a real business yet," he said. "It's whimsical. There's not a lot of whimsical around."

Richard Chin • 612-673-1775