Strange black things ??

[macabethiel]

Over the last couple of weeks some strange black spots / eggs / things have appeared on our conservatory floor.

My first thought was it is fly / insect droppings but they are loose on the tiled floor and can easily be hoovered up.

The first batch a couple of weeks ago numbered about 100 plus and I thought they might have fallen off our Rubber Plant or Tomato plant but they are some distance from both and now another batch have appeared easily another 100 plus.

The ceiling above is white with no cob webs or similar anyone know what they are ?

I have picked some up with tape for the photo the other debris is sand !