The ibis bird, which belongs to the stork family, was regarded in particular as sacred and worthy of burial and mummification. Ibis is also a hieroglyphic symbol. Revered in ancient Egypt, Ibis was associated with wisdom and the ibis-headed god Thoth, who was the scribe of the gods, god of learning, and a deity. Thoth gave the hieroglyph of life to Osiris. Thoth could also be represented as the baboon and North Saqqara was a burial place for both animals.
These burials and shrines at Saqqara became a place pilgrims would come for to pay respects to, especially to the god Thoth. At Saqqara, the cult of the relatively unknown deity Thutmose, a young ibis, was particularly popular among women.
Ibis mummies were mummified with their feet grasped and plunged into a vat of liquid resin. Then they were elaborately wrapped in linen bandages. Often times they were placed into ceramic jars which later were placed into catacombs. Some of the mummies were set rigid with palm-ribs, which was the same technique used on human mummies. Mummification of the ibis included desiccation and evisceration. Large volumes of ibises have been found and understood to have been specially reared in or around the temples. At the Sacred Animal Necropolis at Saqqara, several ibis eggs in a courtyard have been identified as the ibis hatchery. Ibis temples have also provided information for specific breeding sites.
Below is a video link describing the process of animal mummification:
Giakoumis, Melina. "Return of the (Brooklyn) Mummies." Archaeology Magazine. 16 Aug. 2010.
Ikram, Salima. Divine Creatures. Cairo: American University in Cairo, 2005.