Sometimes I put a "good" bug (ladybug etc) on the plant with aphids.
Ants are there too, usually. When the bug notice an ant then bug runs away, fast, panicaly, very panicaly. Often falling off the plant.
The whole scene looks funny, I saw that a few times, wondering - why panic?
Bug is many times bigger than an ant. Also bug has a wings, why is not using it and just fly away?
Last autumn I got the answer:
I was putting ladybug on a plant with aphids. Fast inspection didn't revealed any ant so I put ladybug on a leaf, gently. Maybe second after, my face was still 20-30 cm away, an ant shows up from nowhere - attacking. Attack was fast, very, very fast - imagine a lion attacking from a bush - that's it
Ladybug starts running, most of my body moves back by reflex move too! Ant jumpes on the top of the ladybug which had runed only a few milimeters since attack. Part of a second later they both fall of the plant, ladybug is safe now!
Wow, I saw never anything like that, not so fast, not with an ant
Now, I have my answer.
Bug has no enough time to fly off. Fly off proccess also reveals vulnerable body parts. Running as fast as possible is better, much better.