If a squirrel manages to open your bird feeder, try and fix it before running to the shop to buy a new one. I did that already but my squirrels did not take long before destroying my second one even though it looked so much stronger than the first one…

So, get a small length of old electrical wire. Cut  the rubber outer casing with a Stanley knife (carefully so as not to cut yourself!) and open to retrieve the three strands. Take one of the strands and roughly thread it with the existing netting with pliers to cover the hole.

To keep squirrels away from your feeder in the first place, try the tip in this link (I obviously never reapplied more myself).