I checked my boxes at the reservoir tonight not really expecting to see what I did.
The first box will be gone by weekend hopefully, the second box was a shock. 3 Great Tit ready to fledge at the end of last week are now dead. Another box has fledged though so at least some have got away. The other two active boxes are still going, one should be gone by weekend, the other which was a late take up anyway will probably be the middle of next week.