Two things. For one, when you fall your speed is more or less loosely determined by how ‘tall’ you are, since more height adds more weight but no more air resistance.
Note that ‘tall’ refers to up-down width, so if you’re laying down you’re only like 6 inches tall.
Ants are very short and so fall very slowly.
Meanwhile, when you land, you’re hurt because of all the weight of the top part of you bearing down on the bottom part of you. Again, the taller you are, the worse this is. Since ants are so so so so so much shorter than us no matter what way you lay when you fall, they land much more gently and take much less damage from the impact.
Ants are such small and light, they don’t gain enough speed to get damaged when are flying down. Physics.
Their Weight and wind resistance
They do. Just not under the conditions you’re used to, because the advantages of air resistance and the square-cube law work in their favor under normal Earth conditions. There are other conditions (e.g. the surface of a neutron star) where the ant would be in deep trouble.
Whenever I kick my aunt out of her chair onto the floors, she bitches and cries about her hip.