Swallows and Martins

We saw a Swallow & a young Martin "buzzing" G's radio aerial this am - Anyone know why? Aerial is about 40 ft high and the birds appeared to be trying to get as close to the top of it as possible - It didn't look like they were trying to find a perch but a couple of piccies show the landing gear down!

Swallow & Martin count - 50 plus - mainly Martins
Swallow & martin count- 7:30pm  - 114!