When looking to hire an Arborist to perform work at your house or business, we highly recommend asking to see their Arborist License and Proof of Insurance before they perform any services. Tree work is inherently a very hazardous job, and poor quality work and unsafe practices can both harm the tree and create future hazards, or harm the person performing the work or bystanders, and damage property. Uninsured workers place the burden of financial responsibility on the customer hiring the worker. Maine requires that all licensed Arborists submit proof of insurance to renew their license, but you should ALWAYS ask to see a copy when hiring.