Investigation device

The utility model relates to the technical field of termite killing, in particular to an investigation device which comprises bait wood, a cylinder, a cover plate, a handle, a button, a first push block, a second push block, a third push block, a triangular block and two limiting assemblies. Each limiting assembly comprises a cylinder, a circular ring, a first spring, a mounting column, a push rod, a baffle and a sliding block, a groove is formed in the cylinder, and a third diagonal plane is arranged at one end of the mounting column. When the cover plate is disassembled, a worker presses a button, a push rod pushes a mounting column out of the cover plate, then the worker pulls a handle to enable the cover plate to be separated from a cylinder, when the cover plate is installed, the cover plate extrudes a third diagonal plane to enable the third diagonal plane to move into a groove, so that the cover plate completes covering, and due to the elasticity of a first spring, the mounting column penetrates throug