Well Hillarysmum, we have decided to give 'Glen' another go. Richard Kimble evaded arrest for a significantly longer period of time, so out of respect for that

we have decided that Glen doesn't merit the title. We completely re-did the electric fence, placing three strands of wire...we even criscrossed. Stalag 13 it 'aint, but it's damn close. When the pigs were released back into the enclosure, they were very sedate and only had one exploratory touch at the wire. They then busied themselves exploring their new surroundings.
My second youngest son had to try out the blue tape for himself despite being told repeated that it was 'bold wire'. I think that it's safe to say that the message has now been received and understood. My neice, who is also two seems to be something of an electrical anomaly, she kept holding the wire and laughing. Thinking that there was a weak spot i tired touching it with a blade of grass (better I find than touching it with ones nether regions!). I could feel the little pulse going up the blade, so i was happy enough. Only time will tell if all our efforts have paid off. The pigs seem to have settled more now.... I just hope I don't awake in the morning and find two tamworths digging up the lawn!