Introducing... The VIP latrine!

Regular Pit Latrines, aka Long Drops are pretty much the most basic form of toilets, and are what is used by the vast majority of the world's population. (I can't prove that, but I reckon its probably true!) They are just holes in the ground with a few planks of wood or a slab of concrete over the top which you sit on when you are doing your thing. There is usually a lid over the hole, to stop flies getting in and the smell getting out.

Flies are a big problem because they mess around in the faeces, come back out of the pit and then go and sit on some food, or a person, spreading any bacteria which they might have picked up from the faeces.

In order to reduce the smell, and stop a flood of flies leaving the pit every time you take the lid off the Regular Pit Latrine, some bright spark came up with the Ventilated Improved Pit (VIP) Latrine in the 70's . The difference is the addition of a vent pipe.

Flies which are drawn by smell into the pit are attracted up the vent pipe by the brightness of daylight at the top it, but cannot escape because of the screen (unless they are clever enough to fly back down the pipe and reconsider their choice of escape holes). Wind passing over the vent pipe causes an updraught, removing any smell and helping to draw flies up to the top of the pipe. So now you don't get facaes-covered flies coming out of the toilet. Hurrah!

Here's a pic of a lady called Rosemary, sporting her brand new, and rather pretty, VIP Latrine!

For budding toilet-geeks, check out the myriad toilet options in WaterAid's technology notes.