Watch sending or moving RSS(resources) to a barb.
1. it can be farmed away by others.
2. you can blow the barbs warehouse up and lose the excess rss. So check via scouting what the barb can hold and keep that in the back of your head.
3. as you can see there are a few reasons one sends rss to a barb, normally you wish to send RSS to a barb,timing it so they land just right after you noble it for easy wall build etc.
Now as far as "eating" your RSS when under attack. best thing is to use them up by queuing troops up and or build up some buildings.. You then cancel when the coast is clear and they go back to the warehouse. None of these options are 100% best case scenario as undoubtedly you lose 10% in the cancellation of troops or with the barb stashing ya can be pillaged, BUT ya live to fight another day. Enjoy the game Ozz and welcome aboard, go get em tiger..