I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

Lets, say the Mice are Mice1 and Mice2 and Bottle are WineBottle1,WineBottle2....WineBottle9

== Step A ==
Mice1 drinks WineBottle1 WineBottle2 & WineBottle3
Mice2 drinks WineBottle1 WineBottle4 & WineBottle5

Cases:
If both mice dies, WineBottle1 is the poison bottle.
If only mice Mice1 dies, Either WineBottle2 or WineBottle3 is the poison bottle.
If only mice Mice2 dies, Either WineBottle4 or WineBottle5 is the poison bottle.
If nobody dies, Posion is in WineBottle6 WineBottle7 WineBottle8 or WineBottle9

== Step B(If nobody dies) ==
Mice1 drinks WineBottle6 WineBottle7
Mice2 drinks WineBottle6 WineBottle8

Cases:
If both mice dies, WineBottle6 is the poison bottle.
If only mice Mice1 dies, WineBottle7 is the poison bottle.
If only mice Mice2 dies, WineBottle8 is the poison bottle.
If nobody dies, WineBottle9 is the poison bottle.

== Step2: (Only Mice1 dies - Either WineBottle2 or WineBottle3 is the poison bottle) ==
Mice2 drinks WineBottle2, if Mice2 dies WineBottle2 is the poison bottle else WineBottle3

== Step2: (Only Mice2 dies - Either WineBottle4 or WineBottle5 is the poison bottle) ==
Mice1 drinks WineBottle4, if Mice1 dies WineBottle4 is the poison bottle else WineBottle5

Discussion