Aphis glycines (soybean aphid)
Photo by NSW

You can make a difference. There are many invasive species that have entered the U.S. whose introduction to the environment or spread may be easily affected by what you do. If you keep fish in an aquarium or backyard pond and decide to stop that activity, do not put the fish or plants in a stream, river, lake or the ocean. They may out compete and replace native fish or plants. It is believed that this is the way Caulerpa taxifolia was introduced into San Diego Bay.
When purchasing plants for your yard, realize that many of these plants are from other countries and years after their introduction, some commercially available plants have been found to be invasive. Vast majorities of the commercially available plant species are not invasive, so you have a wide selection of safe plants to choose from. There is much written on the Internet about invasive species found in natural areas; some of the invasive species are even sold commercially. The Internet also provides recommended alternative plantings for these invasivespecies. Exotic pets are easy to find and purchase. If you are tired of your exotic pet, do not release it to nature. Sell it or give it away.