Table 2.

Mellor’s [25] Five Domains Model (reduced and summarized) illustrating positive states and animal welfare. Factors highlighted in bold text suggested as notably relevant to snake positive or negative welfare, and improved by greater space or hindered by lesser space.

Domain	Description
1. Nutrition	Opportunities to: drink enough water; eat enough food; eat a balanced diet; eat a variety of foods; eating correct quantities.
2. Environment	Available conditions: thermally tolerable; suitable substrate; space for freer movement; fresh air; pleasant/tolerable odors; light intensity tolerable; noise exposure acceptable; normal environmental variability; predictability.
3. Health	Little or no: disease; injury; functional impairment; poisoning. Body condition appropriate; good fitness level.
4. Behavior	‘Agency’ exercised via: varied, novel, engaging environmental challenges; congenial sensory inputs; available engaging choices; free movement; exploration; foraging/hunting; bonding/reaffirming bonds; rearing young; playing; sexual activity; using refuges, retreat, or defensive attack; sleep/rest sufficient.
5. Mental state	Wetting/quenching pleasures of drinking; pleasures of different tastes/smells/textures; pleasure of salt taste; masticatory pleasures; postprandial satiety; gastrointestinal comfort; forms of comfort - thermal, physical, respiratory, olfactory, auditory, visual; variety-related comfort; comfort of good health and high functional capacity; vitality of fitness; calmness; engaged, in control; affectionate sociability; maternally rewarded; excitation/playfulness; sexual gratification; secure/protected/confident; likes novelty; energized/refreshed.