Take mustard oil and make it little hot. Then this warm oil inside ear. After few time remove oil from ear in opposite direction. The ant or insect will come come out.
Tilt your head to the affected side and gently shake your head to dislodge the bug. Do not hit your ear as this can lead to additional problems. If the bug is still alive, try pouring a tiny amount of vegetable oil into the ear to suffocate it. If the bug is dead, try to flush it out of the ear using warm water.