There is nothing more irritating than the high-pitched squeal of a mosquito intent on relieving you of some blood as it circles around your head while you are trying to sleep. I've never met a mosquito I liked.
Mosquitoes thrive in hot, wet climates and breed in standing water and their eggs can survive in dry conditions and then hatch a year later if they become wet. Fortunately (or unfortunately in other contexts), Cape Verde is not blessed with an over-abundance of fresh water, yet mosquitoes are found in the islands especially in the rainy season. It's actually hilarious that there is a "rainy" season in Cape Verde - it falls in the second half of the year - because Cape Verde gets an average of about 25 cm of rainfall per year! Believe me, don't pack the umbrella.
But still, these little critters are universally annoying. On many of the online travel sites, the biggest complaint registered by vacationers relate to mosquitoes. Moreover, mosquitoes can transmit dangerous viruses. There was an outbreak of dengue in 2009 in Cape Verde, but not of epidemic proportions. And mosquitoes are also known to transmit malaria in sub Saharan Africa. The government ministry of health, with the assistance of the World Health Organization, took all the necessary steps to minimize mosquito breeding and reduce the threat of mosquito-born illnesses. Today, the likelihood of being infected by either virus is insignificant.
Still, the question anyway is what you should personally do to banish these pests to oblivion and prevent them from ruining your vacation especially if you are in Cape Verde during the period of August through November.
There are several steps you could take.
The first is to travel with and use an insect repellent on exposed skin before heading outdoors. But the real challenge is about what to do while you sleep. One common approach used in countries with heavy mosquito infestations is to use a mosquito-net - but these are not at all common in Cape Verde because mosquitoes are not swarming the place. You typically won't find nets in hotel rooms. Or you could purchase one of those aerosol insect sprays from the local loja and fog your room with it ... but these only work for an hour at most and they produce a horrible, suffocating stench ... you won't be getting any sleep that way.
The most effective solution that I know of, based on experiences in countries where the mosquitoes literally form invading armies, is to burn what's called a "mosquito coil" or "mosquito incense." In Cape Verde, you can find the product in any Chinese loja. And believe me, there is no way you can miss the Chinese lojas ... they are everywhere. I suspect there is 1 Chinese loja to every 10 Cape Verdeans. LOL.
That's a picture of what the product looks like. You'll need matches or a cigarette lighter to set the tip of it burning. The box of coils come with a stand to set the coil on so it can burn without damaging anything (if you lose the stand, just use a beer bottle!) It's a pretty slow burn and one coil will last the entire night. The only downsides are that the burnt coil leaves an ash residue and there is a bit of an odor to the fumes. But you can set the coil on the floor as far away from you as possible and you'll hardly notice the odor. Also, be sure that you don't place the lit coil in close proximity to anything flammable. Remember - the goal is to kill the pesky insects, not to set a romantic mood!
Follow this advice and you and everyone in your room will sleep like a baby, every night. Try not to kick the contraption down as you stumble through the dark on your way to the bathroom! LOL.