over the last 2 days a blackbird has ruined all my seedlings and plants that i have in pots. Its the compost she is after not the plants.i've covered what i can with nets but it moves on to the pots i cant net.i'm blocking the light off to these plants by covering them with wood and things but i can't keep doing that or it's worthless having them. what can i do to stop this and what is in the compost that they want.