One doesn't carry the antidote in the back pack as one doesn't know what snake will bite and they need to be refrigerated anyway.
The process is:
- Get bitten
- Understand what snake bit you
- Apply first aid (snake bit kit)
- Possibly die
- Call emergency services or make your way to assistance yourself
- Possibly die
- Be in agony
- Possibly die
- Get anti-venom
- Be in agony
- Take weeks if not months to recover
As for the rabbits, the stay where they lie, digging graves for them isn't time effective. They get taken by other animals, birds, ants and all and when foxes come around to eat them they get shot too if seen.