Which wasps do you have? Some are pretty gentle and are beneficial because they eat other insects while others, Yellow Jackets up here, are just plain ornery.

grab an adult beverage ... and a lawn chair..

and go sit out there.. near dusk.. and watch where they go ..

i am not aware of any.. gratuitously attacking... and the adult beverage helps your courage.. lol ...

or.. google wasp traps ... and trap one or two.. so we can ID them.. to give you better info ..

some wasps ... the one that make paper nests.. can be controlled as simple as repeatedly wetting the nest ... others you probably dont mess with.. until winter ... if they go dormant ...

ken

Here is a link that might be useful: homemade wasp traps

ifraser, you will have to be your own detective on this one. There are many different wasp species and they have varying habits. I'm not so sure that wasp nests would go dormant in Brazil, but don't know for sure.

Wasps can be solitary or social. Careful observation (as ken suggests) on your part may lead to the discovery of a nest. Whether or not you should do anything about them depends on what they're doing. They typically have their own jobs and don't have time to pay much attention to measly humans.

Now, Brazilian wasps might follow a different set of laws.

Yellow Jackets sting you just because they can. There are good traps you can make with a plastic milk bottle. You just have to put some meat in the bottom with some water and make sure you design it so they can get in but not out. (You can buy the tops at a hardware or garden place.