reingest
/riːɪnˈdʒɛst/Chiefly Zoology
verb
[with object] To ingest (material which has been ejected or secreted from the body); specifically (of a mammal) to eat (its own excrement) to allow secondary digestion.
Origin
Late 19th century; earliest use found in 4th Annual Reports Board of Health State New York 1869. From re- + ingest.