How can snakes smell a rat from?

[Lizardlove]

How far can a snake smell as rat from?

- - - Updated - - -

Trying to find our lost snake and have set a trap with a rat how could my snake smell the rat from?

 

[Trench]

they have very good sense of smell/taste I am not sure how far away they can smell from but if it is the house it will have no problem.
hope you find him
Trench