Most Tachinidae adults are flower fanciers.

Larvae are parasitoids of other insects, primarily larvae of Lepidoptera, sawflies, and beetles. Adult Tachinids feed on liquids such as nectar and the honeydew of aphids and scale insects. Over 1,300 species have been recorded in North America, making the tachinids the second largest family of Diptera on this continent. Important morphological characters include a bristly body, especially on thoracic dorsum and 4th to 6th abdominal segments; postscutellum of mesothorax well developed, protruding posteriorly; pteropleural and hypopleural bristles present. Most tachinids are primary, solitary, endoparasitoids, but some are gregarious parasitoids. They have a wide host range, with all major groups of insects serving as hosts.