In ancient Egypt, offerings were presented every day to a divine being, such as a deity or a king, to appease them or in order to receive a favor. These gifts came in a variety of forms, such as food, drink, and even mummified animals, which were highly respected in this culture. But it turns out that the Egyptians couldn’t quite keep up with all this demand for goods, so they were forced to get a little creative.

After scanning more than 800 bandaged bundles recovered from huge Egyptian tombs, archeologists based in Manchester have found that the Egyptians often cheated when offering animal mummies, wrapping up mud and bits of foliage in place of an actual animal. In fact, this practice was so commonplace that only a third of those analyzed actually contained complete animals.

“We always knew that not all animal mummies contained what we expected them to contain,” University of Manchester Egyptologist Dr Lidija McKnight explains to the BBC, “but we found that around a third don’t contain any animal material at all - so no skeletal remains.”

You may adore your beloved fluffy cat, but the ancient Egyptians took animal worshipping to another level. Not only were they considered crucial to survival, but many were seen as sacred as they believed that their gods and goddesses could appear on Earth in the forms of various animals, particularly birds. Falcons and hawks, for example, represented the god Horus, and cats symbolized the sun god Ra.

Those associated with a deity, or even personal pets, would therefore live a life of luxury and were mummified upon death before being ceremoniously buried. Evidence for such practices has been found at all periods, but during the Late Period (661-332 BCE), the Egyptians began mass rearing animals specifically for sale and subsequent burial as votive gifts to deities in order to establish a relationship with them.

“Today, you’d have a candle in a cathedral; in Egyptian times, you would have an animal mummy,” Dr Campbell Price, curator of Egypt and Sudan at Manchester Museum, explained to the BBC. “You would go to a special site, buy an animal mummy, using a system of barter. You’d then give it to a priest, who would collect a group of animal mummies and bury them.”

But it seems that, despite the establishment of industrial-scale breeding programs, Egyptian mummy makers just couldn’t keep up. This is the conclusion recently drawn by researchers from the University of Manchester and Manchester Museum, who have been busy using X-rays and CT scans to peer inside bundles of cloth recovered from vast catacombs in Egypt. Each individual tomb seems to have been dedicated to one particular animal, and they were absolutely jam-packed with millions of mummified offerings.

Although around one third of those scanned did indeed contain entire animals, which were remarkably well-preserved, the rest either contained partial remains or organic material like reeds or twigs, albeit some was at least associated with a particular animal, such as feathers.

So were the Egyptians really trying to trick the gods? Probably not, conclude the researchers. “We think they were mummifying pieces of animals that were lying around, or materials associated with the animals during their lifetime- so nest material or eggshells,” McKnight told the BBC. “They were special because they had been in close proximity with the animals- even though they weren’t the animals themselves.”