How can lice move from one animal host to another?

Lice move from one animal host to another primarily through direct contact. Because lice are unable to survive for more than short periods away from their host, they rely on close proximity to transfer between individuals.12

In addition to direct contact, some lice can be transferred via other insects. Chewing lice have been observed attaching themselves to louse flies or other insects, which then act as a vehicle to transport the lice to a new host. While a louse may temporarily leave its host to move to another of the same species or even a different species—such as from prey to predator—it may fail to establish itself on the new host if there is a physical or chemical incompatibility with the new environment or food source.1

Host specificity often limits the success of these transfers, as many lice are adapted to survive only on a single species or a group of closely related hosts.1