Let's say the smaller number is x. Then, we can represent the larger number as x + 1. The +1 means that it's both larger, because adding makes a number larger, and consecutive, because it's 1 greater or less.
Then, we can write an equation. The sum of the two numbers is x + (x + 1), and it's equal to -165.
x + (x + 1) = -165
2x + 1 = -165
2x = -166
x = -83
Since x = -83, the smaller number is -83.