Poppy seeds are small, black, and kidney shaped. They have been part of traditional Mediterranean and Middle Eastern diets for thousands of years. In more recent years, they have become more popular in the United States. People have been using them in recipes such as bagels and muffins as well as eating them raw. The seeds come from the poppy plant. Manufacturers use the sap of the poppy plant to make opioid drugs such as heroin, morphine, and oxycodone.