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.
It is the hormone that is also released during other loving behaviors that make us feel good about a person. The surge of Oxytocin while nursing is one of the ways that the mother falls in love with her baby, and the baby benefits as well, because the mother is more likely to interact and care for the infant.