To assist in these stealth moves, the environment contains special areas colored with blue sparkles of light, identified in the game as Sly's "thief senses." The player can trigger context-sensitive actions in these areas, such as shimmying along a narrow ledge or wall, landing on a pointed object such as an antenna or streetlight, climbing along the length of a narrow pole or pipe or using the cane to grapple onto something. The player must avoid detection by security systems and enemies, otherwise, an alarm will sound and the player will either have to destroy the alarm, avoid or defeat foes alerted by the alarm or hide for several seconds until the alarm resets. The game uses a dynamic music system that changes depending on the state of alarm in the area: the music will increase in volume and pacing when Sly attacks or is detected, and then will quiet down as the disturbance goes away.