Although it is true that Grafaiai use their paintings to mark their territory, "territory" has a strange meaning for these pokemon; they gladly welcome outsiders to hold picnics and view their art, and sustain themselves on whatever food they leave behind. It is only other Grafaiai whom these pokemon view as rivals, and they freely vandalize each other's painting trees in the pursuit of local supremacy.
It is, ironically, this perpetual turf war which gives Grafaiai art its distinctive quality. Trees deep in the heart of a single pokemon's realm never attract audiences nearly as large as the battleground trees on the borders. Whether they like it or not, Grafaiai art is a collaborative enterprise: a fact they recognize well enough to seek to take popular trees for themselves, but never well enough to make friends. Grafaiai coalitions are invariably temporary affairs, from which each member can expect to derive personal benefit; even male and female Grafaiai seldom remain together longer than it takes to mate.
Wild Grafaiai only leave forested settings under extreme circumstances, usually as a result of habitat destruction, and only on a temporary basis. The Grafaiai-esque art found on Team Star's bases, or occasionally in urban settings, invariably originates from either trained Grafaiai or from humans who admire this pokemon's style.
Although they are occasionally denounced as a public health hazard, no human deaths can be conclusively attributed to Grafaiai poisoning; the rumor seems to have originated as a metaphor among those who saw their art as 'poisoning' the image of city streets, only to be taken seriously because of their poison typing and connection to Shroodle. A few cities have banned Grafaiai displays, but, as of this writing, no health department has made enforcement a priority; their outlaw status only increases Grafaiai's appeal.