LEV 5:2

2 Or if a nefesh touch anything tamei [(unclean)], whether it be a nivlat chayyah teme'ah [(carcass of an unclean beast)], or a nivlat behemah teme'ah [(carcass of unclean livestock)], or the nivlat sheretz tamei [(carcass of unclean creeping things)], and if it be hidden from him; he also shall be tamei, and guilty.