Luca,
We had a wonderful time in Venice and part of that pleasure was the location and comfort of your apartment. I know it is not custom for Venice apartments to have screens but your mosquitoes were plentiful at the time of our visit. This was not pleasant for us and both Nancy and I had many bites throughout the first night. We learned we needed to keep the windows closed and as a result needed to use air conditioning to cool things off enough to sleep. This is ok for us but to conserve on your energy costs I would suggest that screens would be useful. This is a private note as it is not something we would need to discuss publicly as your place was lovely otherwise. We hope you were satisfied with our cleanliness. We did take care of trash but left a bit of recycle as both containers had some materials from previous users before our stay and it was difficult to find locations for these materials.
Regards,
Bruce