Which of the following tasks can a non-licensed employee perform?

A non-licensed employee can perform tasks that are supportive of veterinary practice but do not require direct licensure. Among the provided options, the use of a signature stamp under a veterinarian's direction is permissible because it involves executing tasks that the veterinarian is overseeing. This allows the licensed veterinarian to maintain responsibility for the treatment while delegating certain non-technical duties to a non-licensed employee.

In contrast, providing treatment without supervision is strictly limited to licensed personnel who have the necessary training and authority to make clinical decisions. Administering vaccines independently would also require a licensed veterinarian's oversight or direction, as it is a medical procedure that carries legal and health implications. Treating animals without consent is unethical and potentially illegal, as informed consent from the owner or responsible party is a fundamental principle in veterinary medicine.