Most of us have heard about mummified people, but a new exhibition unravels the secrets of how the Ancient Egyptians also preserved their pets.
The Walter Rothschild Zoological Museum in Hertfordshire has put on a show of animal mummies - some of which have never been seen by the public.
Many of the mummies were offerings to the gods associated with the creatures.
But some were pets who people wanted to take with them to the afterlife. The exhibition runs until 3 July.
Some of the mummies are wrapped up and museum curators only know what's beneath the bindings because they've used x-rays.
"Some of them are incomplete - for example, their heads are missing," said one of the curators, Jo Cooper.
"Some have an extra leg or an extra wing. They were not put in there neat and complete."
The x-rays are on show too. They have revealed that some mummies were fake - containing only plant remains and a few bones rather than complete animals.
Many animal-headed gods were worshipped
Many animals were mummified with the same care they took for people
The bodies were dried out so they wouldn't decompose
Many organs were removed, but the heart remained because it held the soul
Rich people kept monkeys, baboons and even gazelles as pets
Some of the mummies were unwrapped from their bindings by early scientists who wanted to know more about them.
The exhibits include a mummified bird with its head exposed and a spooky monkey.
Sometimes, mummification occurs naturally, when a body dries out before it decomposes. A perfectly preserved cat can be found in one of the museum's cases.
Exhibition officer Paul Kitching said: "It's just a really cool subject. It's so interesting looking at something that is 3-4,000 years old that you can recognise because it is so wonderfully preserved.
"There is a slight gross factor - you think 'I don't want to look at it, but I will', but it was really fun to put together and research."