Sorry, I didn't know where to open this topic, but can anyone tell me what is this? My sister found it in her house on her book. It looks like nest or larvae I think.

Edited February 1, 20197 yr by ditendra

My guess is that it is the work of wasps that never got finished  into a nest. This is a paper wasp:

Edited February 1, 20197 yr by StringJunky

Thank you for reply. One more thing to add: It's winter, outside is quite cold, but would it be possible for wasps to survive inside the house (to be precise, she's not even living in house, but in apartment on 6th floor of building).

Edited February 1, 20197 yr by ditendra

Mud dauber nest ----> http://www.brisbaneinsects.com/brisbane_apoidwasps/VaseCellMudDauber.htm

Edited February 3, 20197 yr by Externet

Agree it’s a mud dauber. They were everywhere and into everything in Texas. 

Specifically, on the book, it’s a nest they’ve built

Those nests remain even long after any life forms that built them have left or died. 

Thank you guys for helping to identify.