[Jenny Lau]

Here is the sentence: Our conversation sounded less like the cooing of lovebirds and more like the barking of pit bulls.
I don’t know what is "pit bull"? And what does the sentence mean?
It’s from an article written by an American, the following is the context.
The early November storms had melted, leaving an endless landscape of gray trees and mire green earth. It fit our moods. My husband and I vacillated between extreme joy over the life of our two-month-old son and extreme distress over our lack of sleep or time for each other. Our conversation, especially for the past two weeks, sounded less like the cooing of lovebirds and more like the barking of pit bulls.