Get negative value by calling model(dataset)

[TaoXb]

Hi I am very new with yolo and trying tu run some projects to understand. Wenn I tried to use test dataset to get the output from model. Predict () or model(), I am getting lot of negative values, which I don't understand. Because the yolo output is defined in model.py with predictions and so on, which could not be negative...
How does the output structure of model. Predict and model() in this project looks like?
Thanks