I e-mailed Parks and Wildlife about killing snakes and this was their response.
"A landowner or landowner's agent may kill any nongame wildlife other than protected birds and threatened or endangered species at any time in any number, provided the wildlife is not used in a commercial activity. The commercial nongame regulations in their entirety are located at:
Commercial Nongame Regulations
http://info.sos.state.tx.us/pl...
Please note that different possession limits apply depending upon whether a species of snake is legal for commercial activity or not. Species legal for commercial activity may be possessed in quantities of up to 25 without a nongame permit or nongame dealer's permit. Species not legal for commercial activity may be possessed in quantities of up to 6 without a nongame permit or nongame dealer's permit. Nongame permits may be purchased at license counters across the state, and allow for the collection of nongame wildlife and sale to nongame dealers. Nongame dealer permits are obtained through the Wildlife Permits Office at TPWD and allow for the collection and sale of nongame wildlife to anyone. A hunting license is additionally required in order to legally take nongame wildlife from the wild."
