In the United Kingdom researchers are using drones to distribute wireless sensors in hard-to-reach places. Previously, drones would simply drop or place a sensor and hope for the best. Now, the drones are shooting little darts into trees and other surfaces that contain the sensors. Researchers also noted that while the system currently uses darts, they could also utilize chemical bonding, magnets, or adhesive.
Source: https://dronedj.com/2020/10/29/drone-shoots-darts-into-trees-to-collect-data-in-dangerous-areas/