More than 84 million U.S. households have a pet--and it's easy to see why. There are so many positive benefits to having a pet in the house. This list applies mostly to dogs, but pets of all kinds tend to make people happier...and healthier!

1. They relieve stress. Studies have shown that just petting your dog or cat lowers your blood pressure and relieves stress. Science also shows that pet owners have less anxiety, depression and loneliness.

2. Pets help us raise happier, healthier children. Kids who grow up with pets in the house tend to have higher self-esteem and better social skills. And being around a dog when you're a baby is also good. A recent study found kids end up with stronger immune systems and fewer allergies if there's a dog in the house.

3. They encourage us to be more social. Dog owners are five times more likely to know their neighbors than people who don't own dogs. Dr. Alan Beck, Director of the Center for the Human-Animal Bond at Purdue University, puts it best:

"If I saw you walking down the street, I couldn't comfortably start talking to you if I didn't know you, but I could if you had a dog. It's an acceptable interaction that otherwise wouldn't be possible."

4. They're good for your mood. People with pets are generally happier, more trusting, and less lonely than those who don't. Your pet is a loyal companion, which should give you a sense of belonging and meaning, and feel like you've got greater control over your life.

5. They're good for your heart. Dog owners walk a lot more than people who don't have dogs, which helps out your cardiovascular system. But new research also found that any type of pet can also help if you've had a heart attack. 94% of heart patients with pets survived serious heart attacks for at least a year, compared to 72% without pets.

The rewards of pet ownership far outweigh the negatives. Hopefully you've reaped these benefits in your own life!