I think you are overstating what "understanding" is. It is well known that birds see more of the EM spectrum than humans. We can make -- and indeed there are --

I think you are overstating what "understanding" is. It is well known that birds see more of the EM spectrum than humans. We can make -- and indeed there are -- designs that are only visible to birds but are invisible to humans in the sense that our three-cone visual system conflates certain inputs from the physical world. That stop sign can be designed in a way to look like a stop sign to a bird but make us think it is something else entirely. Are we not understanding the stop sign? No. It's just a fact of parsimonious signal representation that sometimes you get null spaces with which you can manipulate to maximally separate the performance of two very different receivers.