Board Thread:Questions and Answers/@comment-108.88.163.33-20140224025650/@comment-3153244-20140224050728

List of upgrades allowing Camo detection: x-2 refers to any upgrade on first path, but tier 2 upgrade for second path.
 * Dart Monkey (2-x)
 * Sniper Monkey (x-2)
 * Boomerang Thrower (4-x)
 * Ninja Monkey (all upgrades)
 * Bomb Tower (x-4 ability only)
 * Glue Gunner (2-4 ability only)
 * Monkey Buccaneer (x-2)
 * Monkey Ace (x-2)
 * Super Monkey (4-x)
 * Monkey Apprentice (x-2)
 * Monkey Village (x-2 allows Camo detection, 4-2 to pop Camos)
 * Mortar Tower (x-3)
 * Dartling Gun (all upgrades)
 * Spike Factory (all upgrades)