One small maggot appeared on kitchen surface and later spotted second one emerging from rsj beam cover crack. both about 6mm long v white coloured. removed rsj covering but nothing found, no tell tale holes anywhere. invesetigated roof space through small hatchway also removed tiles outside to look into roof space, nothing found, no larvae spotted or any dead animal, no wasp/bees nests. roof base tiling board very crumbly but no sign of larvae anywhere and as old house much dust and cobwebs as no scalings or tarpaper on inside of roof space. baffled, usually maggots v numerous when emerging from rotten food so wondered could these be woodworm larvae though not the normal cycle of woodworm but cannot think of any other reason.