Even methane (natural gas) is lighter than air, but not by much. Carbon dioxide, which is contained in the air we breathe out and is also easily and safely manufactured by mixing bicarbonate of soda and vinegar, is heavier than air. It tends to sink to the floor and accumulate. So it's a good job that houses aren't air tight.
Cuddling, holding, and sexual play releases chemicals, like oxytocin, in the brain that create a sense of well-being and happiness, says Dr. Renee Horowitz, an ob-gyn who recently opened the Center for Sexual Wellness in Farmington Hills, Michigan.
Oxytocin is the body's natural wonder drug. It's produced by the hypothalamus in the brain, and released into the bloodstream by the pituitary gland. Oxytocin was the first hormone to be discovered in the early 1900s, when veterinarians noticed that an extract of pituitary gland helped farm animals give birth.