While a bug fly in the air the weight of bug is counter balanced by the buoyancy force that is applied by air on the bug
This buoyancy force is net upthrust on the bug due to air which will help the bug to float in the air
This buoyancy force is given by the formula
[tex]F_b = \rho V g[/tex]
here we know that
[tex]\rho[/tex] = density of air
V = volume of bug
so here we can say that upthrust of air is the force that bug will experience during his uplift
