When the world seems to be angrily knocking at the door, pet owners agree that one faithful companion always adores seeing their face.

Whether it is a slithering snake, a tiny brown hamster or a chocolate Labrador retriever with floppy ears, animals react to their owner's affections -- just as the animal's presence uplifts their owner's spirits.

Although it varies from individual to individual, it is clear that the pet's presence affects an individual's mind and body, said Dan Lago, senior research associate for the Pennsylvania Department of Agriculture and extension education specialist on adult development and aging.

"Through studies it has been shown that blood pressure decreases while an individual is stroking a friendly dog, compared to reading out loud or sitting quietly," Lago said. "It has a calming effect that lasts about 12 to 20 minutes before the blood pressure returns to normal."

Pets also have the ability to affect an individual's spirit and morale, Lago said. For instance, in a study he conducted involving the elderly, Lago said there was a significant change in morale when the elder individual was living alone and lacking other human contact.

However, in his research, Lago said the highest rates of loneliness were found among young people living alone. Although many students do not have time to contend with a puppy shredding the morning paper or a kitten scratching at the beige, leather couch, many want animals to brighten their days.

"I would definitely recommend having an animal because it gets lonely (living without the comforts of home)," said Jana Butterfield (junior-business management). She looks forward to coming home to a lovable, 10-year-old feline.

Opening the front door to a welcoming committee may put a smile on animal lovers' faces. Although a dog's sloppy kisses and rapid wagging tail and a cat's rhythmic purring are blatant signs of approval, owners of pigs and snakes also agree that their animals are capable of giving them enjoyment -- or sometimes headaches.

Eric Edwards (senior-psychology) said owning a Vietnamese miniature potbelly pig, Esther, has kept his hands full. He too, enjoys the company of a pet, although sometimes he gets annoyed by Esther's many demands.

"Anytime she wants something she squeals until you get it," he chuckled. "Pigs are like little kids, they know how to get what they want."

Matt Weisberg (sophomore-political science and psychology) said he likes the violence and excitement exhibited by his 5-foot Burmese python. The snake, Rollins, is a source of entertainment when its powerful jaws engulf a rat every 12-day feeding.

One of the most common worries of students is what to do with the animal when they are at school and work. Lago said often dogs that are left alone experience behavorial problems. So in order for an owner to avoid coming home to shredded paper and gnarled shoes, a pet should be supervised, he said.

Carrie Hoffacker (junior-rehabilitation services education) said this was a concern when she and her roommates were planning to bring a small spaniel to their house next year.

"That was one thing we were worried about," Hoffacker said."But now we know there's always going to be someone there to take care of him."

The degree that a person gets attached to an animal varies with that individual, Lago said.

Tara Dressler (senior-speech communications) said she is attached to her grayish-black hamster because of its gentle, teddy-bear appearance. She affectionately cuddles the animal and incessantly cleans its cage.

"The more personality the animal has, the more effect they have on you, " she added.