9. Keep Your Friends Close...
Damn Antlions, why did they have to choose mating season during a revolution? From point A to B in the fantastic driving section of HL2 (Highway 17), you are hounded by these freaks of nature in ways that don't just unfortunately involve you mowing hordes of them down En Route. Treading carefully on sand in forced 'on foot' sections and creating makeshift bridges from debris to avoid their annoying combat style which consists of them constantly twatting you and then flying about in droves; it easy to see why these are pesky buggers that are a real pain to deal with. That is until of course you learn from a Vortigon (ironically another pesky baddie-turned-goodie from the first Half Life) how to tame them. Using their Pheromones (don't sweat the detail) you are able to make this once frustrating enemy into a pack of cooperative do gooders. And, since you have probably built up a great hatred for them by this point, there isn't much room for sympathy when using them as cannon fodder either, so everyone's a winner. Except the Combine... they never win. Idiots.