Listen to what AggiePam has to say, she has really good information on this issue.
Foxes present us with a unique challenge. If you as a
private citizen trap one, RELOCATION is not a legal option. Your only option with a fox, coyote, or raccoon (there are some exceptions on the coon) is to put it down. Trust me, don't trap a fur bearer without the license. A trapper with the city animal control, or a private trapper contracted through a government agency, DOES have an option of doing a relocation---therefore if trapping is selected, turn it over to city officials. If you load a live fox into your car and head out of town, you are breaking the law.
http://www.dshs.state.tx.us/idcu/health/zoonosis/laws/transport/ Evict and restrict where they have been hanging out (den) is usually the best action to take.
FYI---you can not legally rehab coyotes or fox in Texas
Contact Jesse as AggiePam suggested, he's a good biologist.
Trust me, you really don't want to argue this issue with me