Riddles, brain puzzles and mathematical problems

[BAndrew]

Rat 1:512
Rat 2:256
Rat 3:128
Rat 4:64
Rat 5:32
Rat 6:16
Rat 7:8
Rat 8:4
Rat 9:2
Rat 10:1


Think if it were 2 bottles for instance:

In that case you need 1 (because 2^1) rat to determine which bottle has the poison and not 0 (2^0)


Generalizing the problem you can find a poisonous bottle among 2^n bottles with just n rats.

NOTE: Because in this problem there are 1000 bottles and not 1024 you might need less than 10 rats on very specific cases. However, the minimum safe ammount of rats (in order to be 100% percent sure) is 10.