Hi, I gave a balcony and I tend to keep a bird feeder but lately it's not been in great use, during the time I've allowed my 2 cats to sit oht on the balcony for a little while, these last few weeks I have noticed a pair of dunnocks walking along my the wall but never noticed them feeding from the bird feeder (which I do refresh still just incase) but whenever my cats sit out these birds come out and start tittering away, if they ain't eating from the feeder then what is the issue with my cats? Are they fledglings? Are they protecting something?