Cal. Fish & Game Code § 4005

(a) Except as otherwise provided in this section, every person who traps fur-bearing mammals or nongame mammals, designated by the commission, shall procure a trapping license. Raw fur of fur-bearing and nongame mammals may not be sold. For purposes of this article, “raw fur” means any fur, pelt, or skin that has not been tanned or cured, except that salt-cured or sun-cured pelts are raw furs.
(b) The department shall develop standards that are necessary to ensure the competence and proficiency of applicants for a trapping license. A person shall not be issued a license until the person has passed a test of their knowledge and skill in this field.
(c) Persons trapping mammals in accordance with Section 4152 or 4180 are not required to procure a trapping license except when providing trapping services for profit.
(d) No raw furs taken by persons providing trapping services for profit may be sold.
(e) The license requirement imposed by this section does not apply to any of the following:
1. (1) Officers or employees of federal, county, or city agencies or the department, when acting in their official capacities, or officers or employees of the Department of Food and Agriculture when acting pursuant to the Food and Agricultural Code pertaining to pests or pursuant to Article 6 (commencing with Section 6021) of Chapter 9 of Part 1 of Division 4 of the Food and Agricultural Code.
2. (2) Structural pest control operators licensed pursuant to Chapter 14 (commencing with Section 8500) of Division 3 of the Business and Professions Code, when trapping rats, mice, voles, moles, or gophers.
3. (3) Persons and businesses licensed or certified by the Department of Pesticide Regulation pursuant to Chapter 4 (commencing with Section 11701) and Chapter 8 (commencing with Section 12201) of Division 6 of, and Chapter 3.6, (commencing with Section 14151) of Division 7 of, the Food and Agricultural Code, when trapping rats, mice, voles, moles, or gophers.
(f) Except for species that are listed pursuant to Chapter 1.5 (commencing with Section 2050) of Division 3 or Chapter 8 (commencing with Section 4700), nothing in this code or regulations adopted pursuant thereto shall prevent or prohibit a person from trapping any of the following animals:
1. (1) Gophers.
2. (2) House mice.
3. (3) Moles.
4. (4) Rats.
5. (5) Voles.