鳥 and 虫: visible creatures and audible sounds
Distinguish sound from sight and location from movement when observing birds and bugs.
A bird's appearance and sound
鳥, read とり, means bird. 木の上に鳥がいます。 says that a bird is in a tree.
鳥の声が聞こえます。 says that a bird's call can be heard. It does not also establish that the bird is visible.
A bug's location
虫, read むし, means bug or small creature. 葉の裏に小さな虫を見つけました。 means finding a small bug on the underside of a leaf.
虫が部屋に入ってきました。 says that a bug came into the room. Preserve the inward movement.
Limits of observation
鳥は見えませんが、声は聞こえます。 says that the bird is not visible but its call is audible. Distinguish the visual negative from the auditory positive.
虫を外に出しました。 means letting or putting a bug outside. Do not add killing it.
Does 鳥の声が聞こえます establish that the bird was seen?
Show the answer and why
No. It establishes only that the call is audible.