Probably a very common problem but a first in our house.......for a while now a cat has been coming in and eating our cats food. Laughed at first and tried to shoo it away but now it upsets my cats, one night we woke up with the cat on our landing and ours cowering under the bed! We got a magnetic flap fitted on Sunday, tonight he managed to break through it 
Any tips to deter it....food now out of conservatory, locking cats in at night......
It seems desperate for food, could it be a stray and should you report it or not in case it isn't a stray? It doesn't have a collar and seems pretty keen to eat our food and it's only go cat.....not like we have Sheba down!!