Posted: 15/05/2014 at 20:44
Are you over watering your seedlings Peat, because it sounds as though you are.
Most gardeners only water their seedlings after sowing and the wait till the compost almost dries out before even considering any more water.
If your'e suffering from pests in the greenhouse use staging and put your seed trays on sharp sand to prevent slugs. Us traps for rats and mice. Inspect your seed trays or whatever you are sowing in for slugs before sowing. Disinfect your seed trays/pots before using to guard against fungal infections.
Hygiene in the greenhouse is priority, and are you composting all your veg peelings? Veg peelings will attract rodents, especially potato peelings.