A prediction of the standard LCDM cosmological model is that dark matter (DM) halos are teeming with numerous self-bound substructure, or subhalos. At small scales, subhalos may host no stars/gas at all and thus may not have visible astrophysical counterparts. The existence and precise properties of these ‘dark satellites’ represent important probes of the underlying cosmological model. Also, they may play a key role on the search for DM via its annihilation products. In this talk, I will present current numerical work to characterize the subhalo population with unprecedented detail, and will discuss on the importance that dark satellites may have for DM searches with present or future gamma-ray observatories. I will then summarize the recent efforts we made to search for them in gamma-ray data and to set constraints on the nature of the DM particle using these elusive targets.