Explanation:

Reason for sending Mill-wheel back:
Jody sent Mill-wheel back because he wanted to be alone with the fawn.

Explanation:
There are a few reasons why Jody sent Mill-wheel back, but the primary reason was that he wanted to be alone with the fawn. Let's explore the other reasons as well:

1. Disliking Mill-wheel:
There is no indication in the given information that Jody disliked Mill-wheel. Therefore, this is not the reason for sending Mill-wheel back.

2. Mill-wheel being on the horse:
The fact that Mill-wheel was on the horse doesn't seem to be a reason for Jody to send him back. It is not mentioned that Mill-wheel's presence on the horse was causing any inconvenience to Jody or hindering his plans.

3. Fear of Mill-wheel killing the fawn:
It is stated that Jody feared that Mill-wheel would kill the fawn. This fear might have influenced Jody's decision to some extent, but it is not the main reason why Jody sent Mill-wheel back.

4. Wanting to be alone with the fawn:
The main reason Jody sent Mill-wheel back was because he wanted to be alone with the fawn. Jody had formed a deep connection with the fawn and wanted to spend time with it without any distractions. Mill-wheel's presence would have taken away the solitude and intimacy Jody desired with the fawn.

Sending Mill-wheel back allowed Jody to have uninterrupted time with the fawn, enabling him to bond with it and nurture their relationship. Jody's decision reflects his strong attachment to the fawn and his desire to protect their special connection.

In conclusion, Jody sent Mill-wheel back because he wanted to be alone with the fawn and develop their bond without any distractions. The other reasons mentioned (disliking Mill-wheel, Mill-wheel being on the horse, fear of Mill-wheel killing the fawn) are not the primary motivations behind Jody's decision.