Things left behind by people and things yourself bring in can be altered too useful Items with pliers. Les Stroud uses His Multitools pliers multiple times to turn items left behind by others and items he carrys in himself all the time. One instance of using them to make somthing that can alter your ability to survive in the positive is More then enough to convince me to take um along. This goes without saying other tools such as the philips head screwdriver can come in use as well. You may just need to take a few screws out from something man made you have come across to increase the chance to survive.