On school days, energetic children run down the street, rushing to be first to deposit their backpacks on Nancy and George Axinn's front curb.
It's a game they play. The order of their bags determines their place in the school bus line.
The Axinns have watched this and other rituals since before some of those children were old enough to ride the bus - when they arrived in strollers with their moms and older siblings.
The childhood pastimes - foot races, digging and goofing around - all take place near a bench in the Axinns' heavy-duty gravel front yard.
"Two minutes of raking gets it back in shape" George said.
Some people put birdbaths in their front yard to show hospitality to feathered visitors and to stay attuned to the changing seasons.
Six years ago, the Axinns began doing much the same for some Harelson Elementary School children with a bench.
The children's comings and goings keep them in touch with the school season.
"You really do keep track of when it's vacation and when it's not vacation," Nancy said.
The couple put out a bench not to attract children, though, but to accommodate the ones already flocking to their yard.
The bunch had been discouraged from gathering at another spot - perhaps because it wasn't as safe a bus stop, perhaps because they were causing too much wear and tear on someone else's yard.
Whatever the reason, the Axinns wanted to prove their spot was child-friendly.
"It's one thing to come out and say 'You can stand here and you're welcome,' but putting a bench there was sort of a demonstration that, yes, we really did welcome them," George said.
The bench led to surrogate grandparenthood, with Nancy calling herself Grandma Nancy. That led to the Axinns helping the bus stop kids with school projects, listening to their mini-concerts on band instruments, and buying many Girl Scout cookies.
Which led to party invitations.
"I suppose we wouldn't have been included with all the parents and the kids if we weren't involved with the school bench," Nancy said. "They feel like we are part of the family, too, which is nice."
But the bench project began with a need.
When the Axinns moved to East Morning Sun Court full-time in 1996, after living part-time in Minnesota, they noticed that children and some mothers were congregating near their home in the hot Tucson sun.
They decided to do a bit of outreach.
They bought a simple concrete bench and placed it in the shade of their large mesquite tree. They announced to the mothers that it was a bus-stop bench.
"They were very pleased," George said. "A little surprised, I think, at the beginning, and very pleased."
When pouring rain disrupted bus-stop merrymaking, the Axinns invited the gatherers to stand in their dry garage. Occasionally, if a mother didn't make it to the bus stop on time, the couple invited her child inside for cookies.
After about four years, the bus-stop bench cracked. Perhaps the weather did it; perhaps it was the heavy use.
"I don't think there was any reason for little kids not to jump on it and play games over it and run circles around it," George said.
The couple didn't think twice. They bought a new bench - a sturdier one.
"It became clear that it was going to get a lot of wear and tear," Nancy said, laughing.
The children's bus-stop rituals provide regular chuckles for the Axinns when they choose to focus their concentration on their bench.
There's the ritual with backpacks - the constant contest to see who gets to be first in the bus line.
"They have a real competition over whose bag gets in the line first, you know, and they don't put up with any stuff around that," Nancy said.
Then there are the games the children play in the rocks.
"On our gravelly yard they can sort of scrape it around and make some bare spots and things," George said.
And after the children are safely on the bus, the mothers often hang around to collect their thoughts and plan carpools.
"Some come with a cup of coffee in their hand and when the kids are gone, they'll sit there and chat with each other," Nancy said.
The bench gets used in the summers, too.
Children set up their lemonade stands nearby, and they sit on the bench waiting for customers to arrive. Often the profits are small. Anyone who reaches that neighborhood spot is almost home.
"The children don't pay rent, neither do they share the profits - if they make any," George said. "But sometimes we're the only customers that go out and buy the lemonade."
The Axinns consider their bench low-maintenance outreach.
"We're not monitoring or managing it," George said. "We just have it out there to make them feel welcome."
But it has spurred other forms of outreach.
Once, for example, the couple opened up their home library for a fourth-grader's research for her school project on Bhutan.
George had served Bhutan for two years as its representative from the U.S. Food and Drug Administration.
When the child received an "A" on the project, George offered to help her send a copy to His Majesty, the King of Bhutan.
Since then, other children have used the couple's library.
"You stay interested in their social development and what they're studying and learning about things because you've known them since they were little," Nancy said.
Of course, they do grow up.
Recently, the Axinns ran into one of their former bench users in a restaurant. She was a hostess there.
But new children come. The neighborhood's babies eventually reach school age.
"We've seen them grow up to be old enough to get on the bus themselves," George said.
And that's the cycle of life.
Though most of the Axinns' own grandchildren are now in high school and college, the couple still gets to watch children stepping on the bus in the mornings, and stepping off the bus in the afternoons.
"I think it gives a certain amount of continuity," Nancy said. "You see life going on in the way you'd want it to be going on."