The sites listed below are very useful for finding images for reports and presentations. To be sure you actually have permission to use an image, it is important to search for images that are either in the public domain or that have an appropriate Creative Commons license.
Last Name, First Name (or username). "Title of Image." Name of Website, date, URL.
Fir0002/Flagstaffotos. "Honeybee landing on milkthistle02." Wikimedia Commons, 6 Nov. 2020, https://commons.wikimedia.org/wiki/File:Honeybee_landing_on_milkthistle02.jpg.