If you visit Disney World in Orlando, Florida, once you've stopped being amazed at the sheer level of infrastructure that makes the place hum (and the miles of underground tunnels that aid it), you may also notice something else - in humid, tropical Florida, where you'd expect them to be abundant, there are almost no mosquitoes.
How? It's not magic - the parks are tirelessly designed to avoid any standing water, right down to roof shapes and plant choices, areas are treated with insect-repellent oils, and they keep a close watch via freezing CO2 traps and chickens (which, I didn't realise, don't get sick from mosquito-borne diseases, but still have the viruses in their blood).
The level they go to in order to keep water circulating, including lots of hidden piping, is quite impressive, though. And this all helps because mosquitoes can't fly very far - and given how big Disney World's property is, they're not going to make it all the way to the parks from the outside!
How do you stop an outbreak of rabies in wild raccoons? Roving teams of rangers with darts full of vaccines? Trap-and-release? Of course not - you drop millions of fish-coated vaccine packets from a helicopter.
Lest you think this is a bit of a long shot, a similar program actually virtually elimated canine rabies in the US earlier in the century, so it seems to work well. Bats are one of the remaining big reservoirs of rabies, but they're less keen on the fish-flavoured packets - apparently, trials are underway to try gently misting them with vaccine, which sounds quite pleasant honestly.
The subcontinent of India used to be crossed by a gigantic hedge described as "utterly impassable to man or beast", but as over a billion people can attest, it's not there any more. So where did it go?
It was apparently built (planted?) along a customs line, to deter people from smuggling illegal goods into British-occupied territories - salt, to be precise. It didn't work particularly well, though, as people could just... throw salt over the hedge.
It was eventually abandoned after the need for salt policing was done, but what's most incredible is the idea of using this natural barrier (and tending it) rather than the modern solution of "build a giant wall" - though I guess that also doesn't really work that well either.