The Supernaturalist / Eoin Colfer.

Enhanced descriptions from Syndetics:

In the not-too-distant future, in a place called Satellite City, thirteen-year-old Cosmo Hill is unfortunate enough to come into the world unwanted by his parents. And so, as are all orphaned boys his age, Cosmo is dipped in a vaccine vat and sent to the Clarissa Frayne Institute for Parentally Challenged Boys-freight class. At Clarissa Frayne, the orphans, called "no-sponsors," are put to work by the state, testing dangerous products that never should be allowed near human beings. By the time the no-sponsors are sent to their cardboard utility pipes, given their nightly meal pack, and finally fall asleep, they are often covered in burns, bruises, or sores from the work of the day. Cosmo Hill knows that he must escape, even though he has no idea what might be waiting for him on the outside. He plans for the moment when he can make a break. When that moment finally comes, he nearly dies while escaping. But he is rescued by a gang of "Supernaturalists," a motley crew of kids who all have a special psychic ability-one that Cosmo is about to learn he has as well. They "see" supernatural Parasites-tiny, translucent creatures who feed on the life force of humans. The Supernaturalists