me my mate were out sun put the ferrit down a 1 holer on a bank waited an hour no ferrit the battery went dead on the ferrits collar so blocked it in went back 2 days later with mates cleaned hole out put we jill in 2 3 min came out put the hob in 2 3 min came out both run the set cause we tracked them round the set were do yous think the first 1 went or happen to it it just cant dissapear