Conspirary theory - murmurations are just synchronised swimming for birds. Discuss.

Having a laugh on your birthday is a fundamental human right, so make sure you contribute by sending a hilarious card from the Penny Black funny cards collection!

Blank inside for your own mirthful message, this quirky card measures 12.9cm x 18cm and comes with a matching envelope.

Being kind to the planet is no joke - our cards are printed in the UK on sustainable materials.