As Piltdown says, we have brains (both controllers and pilots) and we should use them.
I'm not sure who the 'them' that van refers to but I'll guess it's meant to be the pilots. As a controller I couldn't agree with this - I'm supposed to clear an aircraft to land or take off only if it is safe to do so. If there's a chunk of something on the runway and I can't tell what it is it's not much help to the pilot to say "Chunk of something or other on the runway, clear to land".
If I see a small - something smaller than a fox, say - dead animal on the runway I'll clear a large aircraft to use the runway, if it's a PA28 then I'll get it cleared away first. If I see something glinting in the sun then I'll get it checked before anything uses the runway. It's a judgement call. And sadly we get less and less opportunity to use our judgement/brains at work these days!