Some people never think about this, but if you live in a house, then your home probably has holes on the outside that could be sealed up. These types of holes usually allow for pipes and appliance hoses to run outside, but they're often much bigger than they need to be. When they are, they're prone to letting air escape from inside your home and driving up heating and cooling costs.
They also sometimes allow bugs and mice to get inside your home, so better to seal them up as soon as possible with a store-bought sealer or foam.