My least favorite animal in Senegal is the mosquito.
They are annoying at best and disease vectors at worst.
Mosquitoes anywhere will suck your blood and leave a mark. Here, they might also transmit a really bad disease, like malaria or yellow fever. To avoid the worst consequences, you spend precious time, effort, and energy to avoid, kill, and mitigate the insects' effects.
And then there is the psychological challenge. There will never be a 0% chance that a mosquito will bite you, or that if one does there will be zero harm. You could work 24/7 indefinitely to mitigate the problem without ever knowing when you have done enough. You do what you are comfortable with, accept the remaining risk, and live your life within the bounds of your remaining freedom.
This is not to say that dealing with mosquitoes in Senegal is any different than, say, software security testing or driving a car. People accept nonzero risks all the time. We do a few things to lower the risk to some acceptable level, and we move on. Here, that means doing the mosquito-equivalent of wearing your seatbelt and driving carefully.
What that looks like differs from person to person. Personally, I do just about everything I can that is reasonably convenient. I wear long clothes and bug spray, sleep under a mosquito net, and take the best available malaria prophylaxis medication (malarone). I also slap dead any mosquitoes I can find during the daytime in places where I usually go. If I can get them before they can harm a human being, terrific.
Fun fact: the malaria-carrying mosquitoes seem to go more or less dormant during the day. Often they will just land and sit on a wall, waiting for nightfall. They will still try to avoid your hand slap, to escape being crushed, but my hit rate under these circumstances is a respectable 70%.
And yet, the mosquitoes always keep coming. There are too many of them. Victory is never absolute. Winning means keeping health risks low, staying vigilant, and, finally, accepting the remaining risk.
Of all of these, acceptance can be the hardest part.
Imagine that it is bedtime, pitch dark. You are lying in your bed after having ensconced yourself under your mosquito net. Lying on your back, eyes towards the ceiling, you have a thought.
"Am I alone under my mosquito net?"
"Am I sure?"
Kids in the United States are often scared of monsters under the bed.
Here, some monsters are real. They live under the bed, on the walls, and in the curtains.