The 20 Most Popular Reader's Photos of 2019

credit: Tony LePrieur / Flickr

From ancient trees and strange sea slugs to odd and adorable insects plus more, our most popular reader's photos of the year are a tribute to Mother Nature.

Readers submit nature photos to our Flickr pool and by email – and our readers are really talented. Photos come from all over the world and feature everything from the vast night sky to the minutiae of an insect's antennae. Each one is a wonder unto itself. While there are no bad ones, the following ten were extra great ... and earned the most views over the course of the year. Which one is your favorite?

20. Sea otter saves the day

sea otter eating purple urchin

© Sam McMillan / Flickr

19. The Needles at sunset

credit: Rick Derevan / Flickr

© Rick Derevan / Flickr

8. Baby stick insect proves that Mother Nature is a mad genius (video)

baby stick insect

© Andreas Kay / Flickr

17. Every circle is a tiny animal

tiny animals

© John Turnbull / Flickr

16. Fuzzy bee sleeps in a flower

Bee sleeping in flower

© marlin harms / Flickr

15. Pika gathers up the grass

American Pika

© Tony LePrieur / Flickr

14. Pirate spider or alien, you decide

Pirate spider

© Andreas Kay / Flickr

13. Beautiful ravens show off their smarts

three ravens

© Tom Van den Bergh / Flickr

12, How are seashells formed?

credit: John Turnbull / Flickr

© John Turnbull / Flickr

11, Why are cardinals so conspicuous?

credit: Richard Liebert / Flickr

© Richard Liebert / Flickr

10. White Mountains hold an ancient secret

white mountains

© Rollie Rodriguez / Flickr

9. 170-year-old fig tree is a majestic beauty

Fig tree

Pete the Poet / Flickr/CC BY 2.0

8. Rainforest hoverfly has crazy moves (video)

hoverfly

© Andreas Kay / Flickr

7. See the tortoise beetle's adorable walk (video)

tortoise beetle

© Andreas Kay / Flickr

6. Sideways glance, owl-style

credit: Tony LePrieur / Flickr

© Tony LePrieur / Flickr

5. Meanwhile in Sweden...

Aurora

© Josefine Karlsson / Flickr

4. Seagoing slug proves truth is stranger than fiction

credit: John Turnbull / Flickr

© John Turnbull / Flickr

3. Spiny devil katydid is strange and adorable

Spiny devil

© Andreas Kay / Flickr

2. Jackrabbit isn't a rabbit at all

Jackrabbit

© Mark Heatherington / Flickr

1. This is what the world's oldest tree looks like

credit: Rollie Rodriguez / Flickr

© Rollie Rodriguez / Flickr