Njoka zaululu ndizofala kuyambira kunyanja mpaka 4000 m. Njoka zaku Europe zimapezeka mkati mwa Arctic Circle, koma m'malo ozizira monga Arctic, Antarctica ndi kumpoto kwa 51 ° N ku North America (Newfoundland, Nova Scotia) palibe mitundu ina yapoizoni sizichitika.
Palibe njoka zaululu ku Crete, Ireland ndi Iceland, kumadzulo kwa Mediterranean, Atlantic ndi Caribbean (kupatula Martinique, Santa Lucia, Margarita, Trinidad ndi Aruba), New Caledonia, New Zealand, Hawaii ndi madera ena a Pacific Ocean. Ku Madagascar ndi Chile, kuli njoka zapoizoni zakuthwa kokha.
Mulga
Krayt
Sandy Efa
Njoka yamchere ya Belcher
Njoka yamphongo
Njoka yaphokoso
Taipan
Njoka ya bulauni yaku Eastern
Krait wabuluu wakuda
Black Mamba
Njoka ya kambuku
Cobra waku Philippines
Gyurza
Njoka ya ku Gabon
Mamba wobiriwira wakumadzulo
Mamba waku Eastern Green
Viper ya Russell
Njoka zina zaululu
Cobra wamtchire
Nyanja ya Taipan
Njoka yam'nyanja ya Dubois
Njoka yovuta
African boomslang
Njoka yamchere
Cobra waku India
Mapeto
Njoka zapoizoni zimatulutsa poizoni m'matope awo, nthawi zambiri zimabayira poizoni m'mano mwa kuluma nyama.
Kwa njoka zambiri zapadziko lapansi, maulosi ndi osavuta komanso opepuka, ndipo kulumidwa kumathandizidwa moyenera ndi mankhwala oyenera. Mitundu ina imayambitsa mavuto azachipatala, zomwe zikutanthauza kuti mankhwalawa sathandiza kwenikweni.
Njoka "zakupha" ndi "zaululu" ndi malingaliro awiri osiyana, koma amagwiritsidwa ntchito mosazindikira mosinthana. Zina mwa njoka za poizoni - zakupha - pafupifupi sizimenya anthu, koma anthu amawopa kwambiri. Kumbali inayi, njoka zomwe zimapha anthu ambiri ndizoopsa kwambiri.
