The eye of a honeybee dusted with pollen, the colon of a mouse colonized with human microbiota, and a human mammary gland organoid grown in the lab are among the top five winning images in Nikon's Small World photomicrography competition. Now in its 41st year, the competition highlights photos taken under the microscope, often by science researchers working in a range of disciplines.

Out of 2000 entries drawn from 83 countries, the four judges—two scientists, a science journalist, and a photo editor at a popular science magazine—chose Ralph Grimm's honeybee eye for the top prize. Grimm is an Australian high school teacher, self-taught photomicrographer, and former beekeeper. It took him four hours to mount, light, and photograph the eye of Apis mellifera, which is magnified 120 times. 

Here are some of our favorite photos (not all are from the top five!), which were shot using a range of techniques, including confocal microscopy, differential interference contrast, and reflected light (Grimm's choice). You can see dozens more in the online gallery of winning pictures. 

3rd Place: Intake of a humped bladderwort (Utricularia gibba), a freshwater carnivorous plant (100x). Winner: Dr. Igor Siwanowicz, Howard Hughes Medical Institute (HHMI), Janelia Farm Research Campus, Leonardo Lab, Ashburn, VA.

4th Place: Lab-grown human mammary gland organoid (100x). Winners: Daniel H. Miller & Ethan S. Sokol, Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Department of Biology Cambridge, Mass.

8th Place: Nerves and blood vessels in a mouse ear skin (10x). Winner: Dr. Tomoko Yamazaki, National Institutes of Health (NIH), Bethesda, MD.

16th place: Feeding rotifers (Floscularia ringens) (50x). Winner: Charles B. Krebs, Charles Krebs Photography, Issaquah, WA.

18th place: Hairyback worm (Chaetonotus sp.) and algae (Micrasterias sp.) (400x). Winner: Roland Gross, Gruenen, Bern, Switzerland

Honorable mention: Detail of jewel beetle (Coleoptera Buprestidae) (32x). Winner: Dr. Luca Toledano, Museo Civico di Storia Naturale di Verona, Verona, Italy