It depends on what they desire. Some become impersonators of children to be nurtured, some simply wish to make a journey towards the light of the moon or the sun... it depends on the species and what each organism intends to gain. Very few come remotely close to a human mindset, and have a very alien way of thinking.

[But he does have a knack for thinking enough along those lines to solve problems with them. It's why he suspects that Wan Shi Tong's drive is less based on desire and more on need, whether or not that's true.]