Midnight 2 year old toddler kicked me on eye. my eyes look fine no redness & during evening when i use to blink there was little pain. next morning lower eyelid was swollen &pain while blinking. so is it because of kick or it's an insect bite?

Doubt it's an insect bite. However, it's worth getting checked by an ophthalmologist to rule out a corneal abrasion, iris or trabecular angle injury and unlikely retinal tear or detachment

It is relatively typical for the hematoma to form with some delay and sleeping on that side might make it worse. It is likely that is all due to the contusion, an insect bite cannot be ruled out, it would just be too much of a coincidence.