The concentric circles（同心圆状斑点）, also known as eyespots on butterfly, not only look like real eyes but may also appear to glare directly at predators（捕食者）from many directions, scientists have found. This visual illusion, called the "Mona Lisa effect", could scare would-be attackers and buy the insects enough time to escape.

Scientists suspect that eyespots, with dark "pupils（瞳孔）" in the center look like real eyes to predators. Hannah Rowland, an ecologist at the Max Planck Institute wanted to see if the direction of this fake gaze contributed to the effect.

First, Rowland and her co-author trained chicks to attack a worm hidden behind a paper printout of two eyespots at the end of a path. When the eyespots' pupils were specifically pointed in the chicks' direction, the birds repeatedly ran toward the paper and then backed away, and they waited a few minutes before attacking. But when the pupils instead appeared to look away from the direction of the chicks' approach, the birds attacked in seconds. Centrally located pupils, though not as effective as ones that stared directly at the chicks, resulted in longer delays than pupils that looked the other way.

"This suggests that they really are paying attention to the direction of the pupils in the eyespots and are perceiving them as eyelike stimulation. The concentric eyespots found most often in the insect world may seem to the chicks like a pair of eyes that follow them regardless of approach angle," says Rowland.

National University of Singapore evolutionary biologist Antonia Monteiro, who was not involved in the research, says the study is a "cool" demonstration of an evolutionary theory for eyespots. "These butterflies can be encountered from all angles, so having the pupil centrally located ends up being pretty good," Monteiro says. Still, she says, the eyespots used in the study were several millimeters larger than even the largest commonly found in nature, raising the possibility that the chicks may have been extra frightened by the size of the paper eyes.

Jeremiad Oleita thinks she may have a partial solution for two of our country's persistent problems: garbage and poverty. It's called the Chip Bag Project. The 26-year-old student and environmentalist from Detroit is asking a favor of local snack lovers: Rather than throw your empty chip bags into the rubbish, donate them so she can turn them into sleeping bags for the homeless.

Chip eaters drop off their empty bags at two locations in Detroit: a print shop and a clothing store, where Oleita and her volunteer helpers collect them. After they clean the chip bags in soapy hot water, they slice them open, ay them flat, and iron them together. They use liners from old coats to line the insides.

It takes about four hours to sew a sleeping bag，and each takes around 150 to 300 chip bags, depending on whether they're single—serve or family size. The result is a sleeping bag that is "waterproof, lightweight, and easy to carry around, " Oleita told the Detroit News.

Since its start in 2020, the Chip Bag Project has collected more than 800, 000 chip bags and, as of last December, created 110 sleeping bags.

Sure, it would be simpler to raise money to buy new sleeping bags. But that's only half the goal for Oleita—whose family moved to the United States from Nigeria a decade ago with the hope of attaining a better life—and her fellow volunteers. "We are dedicated to making an impact not only socially, but environmentally, " she says.

As Oleita said, "There's the symbolism of using bags that would otherwise land in the rubbish and using them to help the homeless. It's a powerful reminder that environmental injustice and poverty often go hand in hand. "

Anyone interested in easy ways to make a positive impact on their communities need look no further than 12-year-old Danykah Muck, a Michigan middle-schooler whose simple learning project is an inspiration to positive thinkers of any age. It all started with her way to school every school day. Every morning she would greet an old man in her neighborhood, who she still doesn't know his name, smiling or even simply offering a friendly word "hello". And he would always nod and smile back. "It seems to considerably change the emotional energy around me in the community," She noticed this in both directions, "That simple act can both change our entire day with how they greet me."

Last spring, Muck brought an idea to her teachers. She provided them with a pile of sticky notes she had filled with brief — sometimes one-word — positive messages. She then asked the teachers to place the notes on students' desks before they arrived at school the next day. She also gave pre-filled sticky notes to the lunch staff and to school administrators including the principal. The idea was to make it easy for teachers, staff and students to regularly encounter reminders that they matter and are valued. "You are enough just being you," reads one favorite note. Muck's idea could be just the thing in an office, assisted living facility or even at home for a small family.

"Low-cost" positive interactions, like a friendly word offered to the postal worker or coffee shop servant, are shown by psychology researchers to build sympathy and abate loneliness. An anonymous note sent into someone's inbox or stuck to their front door is perhaps the lowest-cost connection there is, with potential benefits beyond our imagination. Sometimes the smallest encouragements have the biggest impact. What would you say on a sticky note to share with someone in your community?