They often host guests on their city-ships. Timothy Sinclair and Vash traveled extensively with the Lalairu during the late 2350s. The Laihae sensed something special about Sinclair, and called him a "true seeker." (Star Trek: Pendragon: "Past Watchful Dragons")
The Lalaru were created by author Diane Duane for her book Dark Mirror. In the TNG novel Intellivore (also by Diane Duane), a radically different version of the Lalairu was mentioned. These Lalairu were a single species, not a group. The Lalairu grow cloaks while outside their own ships which they shed when returning. Jean-Luc Picard became one of the few people to see a Lalairu without its cloak in 2371. Lalairu count a person's experience by the number of times one dies, for they have the capability to regenerate after death even if only a single strand of DNA remains. There were problems at the Lalairu's first contact with other races until they were made to understand death was permanent for most species.
It seems as though Duane forgot the information she had already established about the Lalairu in Dark Mirror, and no editor caught the error. In the subsequent Rihannsu novels, though, the Lalairu were as depicted as they were originally.