mobs can see through blocks

Sorry, i didn't realized if this has been reported before. You can delete this post.
Creeper and any mobs can see through any solid blocks, wood, stone, etc. I can't hide from creeper. Because he destroy my house and i'm dead after sleep. Is that normal?
Acer z205 android kitkat 4.4.2. Minecraft pe 0.15.90.7