What are the black boxes in the garden and shrubbery areas at POR?

[melissarose]

I meant to ask this right when we got back but then I forgot. We saw a lot of this small black boxes in the gardens and grassy areas with lots of shrubs. They had a hole in one side and looked to be latched shut. We even saw a few right up against some of the buildings. We thought they might be for catching snakes?

 

[Wcpedorc]

I meant to ask this right when we got back but then I forgot. We saw a lot of this small black boxes in the gardens and grassy areas with lots of shrubs. They had a hole in one side and looked to be latched shut. We even saw a few right up against some of the buildings. We thought they might be for catching snakes?

Rat traps

 

[OKW Lover]

Covers over the utility (water most likely) controls.