RI, MA EHS Pest Control Blog

Research Uncovers Empathy in Rats

As charges of greed and self-interest fly in these hyper-partisan political times, humans might do well to look to rats for lessons in kindness and caring.

A University of Chicago experiment to determine how much empathy rats have for each other had some surprising results, which were published Friday in the research journal Science.

In laboratory studies, a rat was restrained in a small cage that could be opened only from the outside. A second rat, seeing the predicament of the trapped rat, immediately began tirelessly trying to find a way to free his fellow rat.

Eventually, the second rat taught itself to open the cage door, freeing the restrained rat, leading to what strongly resembled a triumphal celebration between the two. Even when faced with an alternative choice of chocolate chips, the free rat would not be deterred from helping its caged fellow rat.

As simple as it sounds, the experiment is being hailed as a new paradigm that will help scientists trace the development of emotion in mammals back through the evolutionary tree.

Previously, scientists thought that empathy and pro-social behavior to help others were unique to humans, said Jeffrey Mogil, a researcher at McGill University in Canada who has done similar studies on mice.

“This study shows the roots of human empathy didn’t just appear but evolved,” said Mogil, who was not connected with the University of Chicago study. “It is very impressive, showing really robust and conclusive evidence that rats show pro-social (helping) behavior. You can argue why the rats are doing it, but you can’t argue anymore that the rats are doing it.”

The experiment is the work of University of Chicago doctoral student Inbal Ben-Ami Bartal; her adviser, Jean Decety, a professor of psychology and psychiatry who studies human empathy; and Peggy Mason, a neurobiology professor who studies pain modulation and relief.

Decety said it has been proved in past studies that rats also experience a primitive form of empathy called emotional contagion — the sort of thing where if one baby in a group of babies begins to cry, they all break out in tears.

“Ben-Ami came to my lab to do her Ph.D. with an idea of using an animal model to study higher forms of empathy,” said Decety, who enlisted Mason for a study that wound up taking three years.

The team first paired rats of the same gender for three weeks.

Then they placed one of the pair in a small, Plexiglas restraint cage, locked by a door that could only be opened from the outside. The cage was placed in a larger enclosure where the rat’s partner roamed free.

By means the researchers aren’t sure of, the caged rat seemed to communicate its distress to the freed rat, and the freed rat sprang into action.

“The free rat jumps on the restraining cage immediately, pushing it, biting at it, touching its nose and whiskers through the openings in the restraining cage with those of the trapped rat,” Mason said. “Clearly it wants to help out the trapped rat.”

After about six days, the free rat would accidentally open the door and from then on quickly learned how to deliberately open it, and then excitedly interact with its now-free partner as they raced around the enclosure.

“I can’t say that they are celebrating,” said Mason. “But sure looks like a celebration.”

Because rats love chocolate, in some experiments the scientists placed two restraint cages in an enclosure with a rat that already knew how to open the cage door. One cage contained a rat, the other five chocolate chips.

“We wanted to ask how much the free rat valued being able to liberate the caged rat,” Mason said. “They like their chocolate chips, but the free rat would open both cages in no particular order.

“The free (rat) could have done all manner of things to monopolize the chocolate chips, but on average it always left one and a half chocolate chips for the liberated rat. That’s impressive — a hard thing for primates to do — showing it puts equal value on chocolate and freeing its partner.”

Eventually rats that did not know each other were used, and the free rat still worked hard to liberate the stranger from the cage.

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA 

HantaVirus Found in Trapped Rodents

Six rodents trapped during routine monitoring in the last week in North County and East County have tested positive for the potentially-deadly hantavirus.

Infected rodents rarely pose a danger to people if they are in the wild and there has been just one non-fatal human case in the county, in 2004. But people can inhale hantavirus by stirring up rodent droppings, then get sick and even die. There is no treatment, vaccine or cure for hantavirus infections, which are deadly in 38 percent of cases.

“People should never sweep up or vacuum rodent droppings or nesting material when they find it,” said Jack Miller, director of the County Department of Environmental Health. “Instead, they should ventilate closed areas for at least 30 minutes, and then carefully use bleach or a full-strength disinfectant before removing them.”

The best way people can prevent the disease is to keep mice out of houses, garages and sheds by sealing holes larger than the size of a dime, County officials said.

Hantavirus can cause hantavirus pulmonary syndrome (HPS), which begins with flu-like symptoms but can grow into severe breathing difficulties and even death.

The rodents that tested positive during the last week included: two deer mice from Campo; one deer mouse each from Carlsbad and Escondido; one harvest mouse from Oceanside and a vole from Carlsbad. Thirty-seven rodents have tested positive for hantavirus in the county this year, compared to 21 in 2010.

Source: Associated Press

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA

RESTAURANT TO BE SHUT DOWN OVER RODENT DROPPINGS

Call it a big but disgusting find for kitchen cops in Brownsville.

An eatery is busted with rodent droppings “all over” the kitchen area.

The New Courthouse Coffee Shop on 964 East Harrison scored 38 demerits.

It was the dirtiest kitchen featured this week by the Food Patrol.

Food handlers were caught wearing open-toe shoes and not wearing hairnets or washing hands.

A health inspector noted on the report how there were “a lot of rodent droppings all over the kitchen.”

Dirty photos of the kitchen area showed trails of droppings on the food prep table and torn bags of food believed to be from rodents.

The Food Patrol confronted the owner’s sister who was present during the health inspection.

Gracie Gutierrez admitted the kitchen was dirty.

She blamed a worker for not doing her “job.”

Food Patrol fans who saw the dirty photos called for the coffee shop which serves food to judges and attorneys to be shutdown.

Source = Valley Central.com

George Williams
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA

More Rodents Carrying Hantavirus Found

Six more rodents trapped by County Vector Control technicians last week have tested positive for the sometimes-deadly hantavirus, County officials said this week.

The rodents, four Harvest mice and two California Meadow Voles, were trapped in Fairbanks Ranch and northern Escondido near the San Luis Rey River bringing this year’s total to 16 rodents testing positive for hantavirus, a news release stated. In 2010, a total of 21 rodents tested positive for hantavirus.

“Recent rains have created an abundance of food for rodents, which can increase the rodent population,” said County Environmental Health Director Jack Miller. “More rodents can lead to more hantavirus.” People should never sweep up or vacuum rodent droppings and nesting materials. Instead, ventilate closed areas and use wet cleaning methods with a 10 percent bleach solution or other full strength disinfectant. The best way to prevent the disease is to keep mice out of houses, garages and sheds by sealing all holes larger than the size of a dime, the news release stated.

Wild rodents, primarily deer mice, carry hantavirus. People can contract it by inhaling dust particles from rodent droppings and nesting materials that contain the virus. The virus can cause hantavirus pulmonary syndrome (HPS), which begins with flu-like symptoms, but can graduate to severe breathing difficulties and even death, according to the news release. There is no vaccine or specific treatment for hantavirus and the national Centers for Disease Control and Prevention report that HPS has killed 36 percent of all the people known to have contracted the disease.

How to Avoid Exposure:

• Eliminate rodent infestations immediately.
• Avoid rodent infested areas. Do not stir up dust or materials that may be contaminated with feces and urine.
• Clean up rodent droppings and urine using the wet cleaning method described below.

Use “wet-cleaning” methods to prevent inhaling the virus:

• DO NOT SWEEP OR VACUUM INFESTED AREAS.
• Ventilate affected area by opening doors and windows for at least 30 minutes.
• Use rubber gloves. Spray a 10 percent bleach solution (2 tablespoons bleach to 1 cup of water), or other full strength disinfectant onto dead rodents, rodent droppings, nests, contaminated traps, and surrounding areas and let the disinfectant stand for at least 15 minutes before cleaning. Clean with a sponge or a mop.
• Place disinfected rodents and debris into two plastic bags, seal them and discard in the trash.
• Wash gloves in a bleach solution, then soap and water, and dispose of them using the same double-bag method. Thoroughly wash your bare hands with soap and water.

George Williams,
General Manager - Staff Entomologist

Pest Control, RI, Pest Control, MA

(click to enlarge image)

Rodents have lanolin on their fur that causes tell-tale rub marks in heavily traveled pathways. Lanolin is yellow viscous oil in the fur that is made of fatty acids and esters. It allows rodents to squeeze into tight voids & spaces with great ease.

We know that when we do a rodent inspection that this is one of the signs we look for to determine activity. The more frequently traveled in the same area means there will be a buildup of lanolin. To the untrained eye it looks like oil but to us it is an important find that will aid in control because it tells us that it is a rodent highway.

The attached image shows the rub marks leading under a wooden deck.

by Ryan Metterville, Service Specialist