Common noun for the insect. No special usage restrictions.
A line of ants had formed under the park bench.
ありが砂糖に群がっている。
Ants are swarming over the sugar.
A trail of ants had formed in the kitchen.
Ants appear in the garden when summer comes.
I got stung by an ant in the grass.
I exterminated the ants with insecticide.
anthill; ant mound