Birds nests keep falling on my head :) ?

[dazzz]

I have about 3 rai of land which is  full of big trees and lots of nests as i like birds and encourage  them  to nest there . Very strange this week 5 nests have falling out of the trees for no apparent reason except bad nest building ?There have been no winds or anything . The nests are all the same just made of grass by a small sparrow .
 The first nest i ignored as i thought the birds had gone but the next 4 nests 3 had young and the one in the photo had 4 eggs . All the nests are right on the end of branches  but  the grass does not seem to be bound or entwined around the branches ? Never seen this before . Anyone any ideas ?

[Kwasaki]

Simple Thai farmer builders,  Thai bird nest builders. 

Put a load of birdhouses in the tree's. 

[whiteman]

You sure it is a birds nest and not your wig been blown off :)

 

[katana]

Maybe some animal predator after eggs or chicks...

[dazzz]

13 hours ago, whiteman said:

You sure it is a birds nest and not your wig been blown off :)

 

Well i am a slap head but no not my wigs but may use as a wig as they were not much good as nests. The last nest that fell with the eggs in is already being rebuilt .
 I dont think predators as right outside my house and the dead chicks were still there being eaten by ants . did see a cobra get a frog a few metres away but i dont think they climb trees .
 I had a thought though . These birds have been nesting in the side of the shelter of my house for years and these birds are probably last years young and no room at the inn but they only know how to build house nests and not tree nests  or maybe i have had to much leo and should give up thinking
dazzz