You see that wall?

A group of vampire bats are hanging out in a cave. All the food in the area is gone and they are the brink of starving to death. One of the bats decides leave to look for food out of desperation. He comes back 30 minutes later and has blood on his face. The other bats are very curious and ask him repeatedly where he got the blood from. Each time, he tries to ignore them and says he doesn't want to talk about it. After 30 minutes of questioning, he breaks down and tells the others to follow him. He flies them to a huge mountainous wall 15 minutes away, and stops. He looks at the others and says,

'You see that wall?'

And they all exciteldy repeat, 'Yea yea, we see it!'

He says again, 'Do you really see that wall?'

They all say again in anticipation, 'Yea yea we see it!'

'Well I didn't!'