Dog is acting as though she can see things we can't

My 2 year old Border Collie has just started pouncing on nothing and going around the house as though she is looking for something or can see something (as I imagine she would if she could see an insect)
She has just ate a meal and seems okay apart from that but it is very disconcerting to see. Any one any ideas please

No real idea why, but earlier this evening our pup did the same thing, it was like he could hear or see something and was on alert and sniffing around and yet we could see nothing and couldnt work out why, which we have not seen him do before.

We've had a few late flies around the house recently, and Max has been stalking them... snapping in mid air, or jumping at seemingly 'nothing'.... he did catch one the other day, but he ate it

Could she have seen a fly?

I don't think so, I did wonder if she had seen an insect and as she's a bit 'neurotic' kept looking for it but she's doing it while sitting in the chair. She has had a dirty ear which makes her put her head on one side but we cleaned it out and it seemed to improve but I wondered if her balance is still a bit off and that is disturbing her. I think if still like it in the morning will take to the vet

When there was a fly, Max wouldn't settle at all. He paced round the room all night, stalking and pouncing. I couldn't hear anything, but he obviously could. It did freak us out for a bit, specially as Murphy wasn't bothered by it at all and was acting normally

typical sounding border collie trait, but a trait that can be indicative of boredom.

check with your vet anyway.

Yep, an ear infection can cause this type of thing. Although I agree with KW that collies can pounce and look for things that to us aren't there, if this is sudden behaviour and out of character for her, then at the age she is I would suspect a possible medical reason behind it

Thanks for all the advice,
this morning she seems a lot better, still caught her doing it a few times but certainly much less than last night. Hopefully one of those odd things that happen. Will keep an eye on her today - daughter convinced some kind of brain problem!!

Mice. Under the floorboards.
It`s more than likely to be her hearing or scenting things. My last pointer would stand in a field for hours intently staring at the ground.. then pouncing when the mole surfaced.

You beat me to it i was just going to ask if they had floorboards because it could be mice