In the story Earth has colonised space; its forces track the Adharan ship but they misread their activities on the annexed planets. The Adharans are not poaching treasure, they also are colonising by leaving their eggs there.
The Terrans have assumed that the Adharans - arachnid creepy crawlies- are a lesser species, mere 'poachers' but the irony is that they harbour the same colonial/ colonising impulse. With our removal of their eggs back to Earth in the mistaken belief they are treasure, they are now on the verge of colonising us!
Maybe this disaster could have been averted: the subordinate Barnes says "How is communication with this race possible?" He at least is alive to the fact that some kind of dialogue is desirable; then perhaps the Adharans would have communicated that the store is their offspring, not exotic jewels.
Meanwhile, the Adharan commander exclaims 'But what would the Terrans want with our eggs? Nothing but trouble will come, when hatching begins ....Terran minds are beyond comprehension". They certainly weren't trying to trick the humans into taking the eggs back to Earth and the whole episode is a tragic misunderstanding which could have been avoided if there had been an attempt at communication by the humans.
This theme of lack of communication is conveyed by the point of view from which the story is told. It is told from two distinct points of view, only the Adharan point of view giving the truth of the matter. Earth must try to communicate with other species in order to understand them and their goals. No doubt, Phillip Dick also has in mind encounters between colonial forces and other peoples here on Earth; here also there has been a lack of communication and understanding.