They certainly react to different concentrations.
Above 70%, Deet works great - below 40%, not so much
With Picaridin, the little ~5% vials are not effective, but the 15% spray works OK with lower numbers of skeeters. ditto for 30% lemon eucalyptus.
In swarms, it is 100% deet and/or a headnet and clothing coverage.
Don't hike in swarm season anymore, but when I did, stuck a burning mosquito coil and holder to the top of the trekking pole. It actually helped quite a lot - kept me sane.
There was some buzz about catnip oil a few years back, but nothing developed.
Tried everything else - none of it worked at all.