Human-sized, yeah. Wouldn't be so bad if the entire world wasn't flooded with them. It's a neverending stream. [ He almost feels compelled to defend his world's dangerousness. The fact that Levi's home might be worse feels almost like an attack to the suffering his own home had been put through. ]

Music is the safest way to get rid of them. Lucille's voice can literally blow them up. [ He hates Lucille's guts but that is kinda cool. ] But destroying the head keeps them from moving pretty well. To be sure they won't get back up you need to burn them to ashes though.