Snake

• Eighty-four percent of pet owners say that their pets have a mostly positive impact on their mental health, similar to last year’s polling on the topic.
• “It’s easy to overlook the role of pets when we’re talking about mental health,” said APA President Petros Levounis, M.D., M.A.
• “From offering companionship and unconditional love to reducing stress and anxiety, pets can be invaluable sources of comfort and support.
• One in five (18%) of those with pets said one or more of their pets was certified as an emotional support animal.

• These robots could come in handy in search-and-rescue situations, where they could navigate collapsed buildings to find and assist survivors.
• With slender, flexible bodies, limbless robots could readily move through confined and cluttered spaces such as debris fields, where walking or wheeled robots and human rescuers tend to fail.
• However, even the most advanced limbless robots have not come close to moving with the agility and versatility of worms and snakes in difficult terrain.

Undulators and mechanical intelligence

• Our team wanted to figure out a way to simplify these systems by highlighting mechanically controlled approaches to dealing with obstacles that don’t require sensors or computation.
• Animals don’t rely solely on their neurons – brain cells and peripheral nerves – to control movement.
• While computational systems are governed by the laws of mathematics, mechanical systems are governed by physics.
• To achieve the same task, scientists can either design an algorithm or carefully design a physical system.
• If you compare a diverse set of undulating organisms with the increasingly large zoo of robotic “snakes,” one difference between the robots and biological undulators stands out.

To get to the bottom of this question, our team built a new robot called MILLR, for mechanically intelligent limbless robot, inspired by the two bands of muscle on snakes and worms. MILLR has two independently controlled cables that pull each joint left and right, bilaterally.
We found this method allows the robot to spontaneously move around obstacles without having to sense its surroundings and actively change its body posture to comply to the environment.

Building a mechanically intelligent robot

• This way, it mirrors the muscle activation methods that snakes and nematodes use, where the left and right sides take turns activating.
• This activation mode pulls the body toward one side or another by tightening on one side, while the other side relaxes and is pulled along passively.

• When the robot collides with an obstacle, depending on the cable tension, it selectively maintains its shape or bends under the force of the obstacle.
• If, alternatively, the robot experienced a force that opposed the bend, it would remain rigid and push itself off the obstacle.

Testing MILLR

• We sent MILLR through a similar course and compared the results.
• We noticed that the worms made the same type of body movements when they collided with obstacles as MILLR did.

This work was supported by the National Science Foundation Physics of Living Systems Student Research Network, NSF-Simons Southeast Center for Mathematics and Biology, Army Research Office Grant, and the Dunn Family Professorship.

• A staggering eight in 10 people who have rescued a pet from a shelter say it is the most rewarding thing they have ever done.
• Almost six in 10 (59 per cent) believe they have "saved its life" and 30 per cent feel fulfilled by bringing it into a loving home.
• For 59 per cent of adopters, the belief that they have "saved a life" is a significant factor.
• Martina McChowat, Brand Experience Lead for Purina.co.uk, said: "Pet adoption allows people to make a compassionate choice, however it should be considered carefully.

• In fact, research in one part of rural Australia found 38% of respondents tried to kill snakes wherever possible.
• Despite their fearsome reputation, venomous Australian snakes pose little risk to human health.
• We found adult eastern brown snakes can collectively remove thousands of mice per square kilometre of farmland each year, which substantially increases farm productivity.

A persecuted serpent

• Brown snakes are the most common deadly snake species found in disturbed agricultural habitats in the southern half of Australia.
• Brown snakes are generally persecuted in rural areas because the danger of fatal snake bites is seen to outweigh their benefits as pest controllers.
• It’s true that brown snakes are the most common cause of fatal snake bite in Australia.

An upside to venomous snakes

• We wanted to calculate the number of rodents removed from Australian farmland by brown snakes.
• To estimate the abundance of brown snakes on farms, we consulted previous research on brown snake abundance, and rates of capture from fieldwork involving red-bellied black snakes.
• Based on the combined data, we found a square kilometre of farmland can contain 100 adult eastern brown snakes, even where rates of encounters between people and those snakes are low.

Give snakes a chance

• Agricultural productivity gains are not the only benefits of tolerating brown snakes on farmland.
• Culling snakes may create an influx of new animals unfamiliar with the location and not used to humans.

• The obvious rebuttal is that killing snakes reduces the incidence of future snake bite, by reducing overall snake numbers.
• Our findings suggest the need for a more balanced view of the costs and benefits of snakes, including brown snakes.
• Tolerating them may bring benefits that outweigh the already low chance of life-threatening snake bite.

Rick Shine receives funding from the Australian Research Council.