Yoku's Island Express

There are a total of 41 scarabs in the game that need to be activated. It's important to know what they are and to look out for them as you progress, but only to avoid a lot of unnecessary backtracking later in the game. Since the game doesn't really explain scarabs, when you come to the pinball areas of the game, you'll possibly notice the outline of a scarab near various lanes and targets in the pinball sections. To activate the scarab, you need to continually pass through that lane or hit that target over and over until the scarab becomes fully colored, at which point it'll spew a bunch of fruit onto the pinball area.

These scarab outlines are sometimes obvious, but some are a little tough to notice if you aren't looking for them. I highly recommend actively looking for them every time you get to a new pinball area. To make this easier, there is a map over at IGN, found HERE, that has all scarabs marked on the map. It's much more efficient to activate each scarab as you progress, and I recommend doing so. There will be a couple scarabs that you won't be able to activate until you acquire a later ability, but the majority can be activated immediately.

Note that any scarabs you miss will be marked on your map as well, with the same blue circle with a line through it, which is used on the map linked above. Using the map is more helpful for ensuring you don't move on before activating each one, or if you think you've found them all but are possibly missing one.