Sharing trivia with friends has never been easier in our age of social media, but there's still something charming about sending something through the mail. Amazing Animal Facts—previously a book and now a box of cards—allows you to send info-packed notes to your friends and family. The postcards feature animal-related facts along with illustrations by Sweden-based artist Maja Säfström.

The box set, which includes 50 cards, has five categories to choose from: sea, forest, field, jungle, and sky. Each card is dedicated to a different animal and comes with one to five different facts about the species. (For example, did you know that blue whales have belly buttons?) As a fun twist, all the cards are in black and white, so you can customize and color them to your liking. Once you finish coloring and adding a personal note, you can apply a stamp and pop it in the mail.

You can grab one of these sets on Amazon for $20.





Know of something you think we should cover? Email us at tips@mentalfloss.com.