What are "Thimbles"?

So I'm heading over to Jersey sometime tonight. I'll be meeting with a man and his 5 year old daughter who claim to see small (3-4 foot tall) alien beings, creatures?

I've gathered some background info from our conversations.

He lives in a house that has been converted into 3 apartments, the other two apartments are vacant. If I have the time I'll do what I can to track down the past tenants to see if they had experienced any unusual activity as well. He's occupied the residence for 3 months now. Within the first month of moving in his daughter was claiming to see little people in her room and outside her bedroom window, which she's dubbed "thimbles". (I'm curious to see why she would call them that.) Shortly after that her father consistently began seeing things out of the corner of his eye. He told me he had set up cameras in the apartment but was unable to catch anything... BUT! Recently I received another call from him raving how he thinks he may have caught a glimpse of one on his cellphone.

Well, time to pack up! After this I'm on my way to another.

I can't wait to show you all what I find!

Take care!