[walshie]

Had a word with the beekeepr who's put up a mesh fence beside the hives. Seems to be doing the trick so far. (Fingers crossed.)

[DavidandCollette]

Two other reasons.  If your visitors are wearing perfume/hair products that can also cause them to attack. Have you had a large crop in the vicinity that has finished  flowering eg rape ( I don't know where you are)they can get very may of their supplies have suddenly died up

[devonlady]

One of my current hives is 'angry' I found that out when i opened them up, but they are curently queen less,  they will settle down once they sort that out.

Newbie question:  How are they going to do that then? 

Left to themselves they will feed a worker special food to turn her into a queen. Fascinating!

[HesterF]

Mine were very feisty after the rape went over last summer - apparently normal, like taking away a kid's sweets. They also flare up with bad weather and by autumn were really horrid. I thought I was going to have to requeen this year but they were so lovely last week I've nearly forgiven them. The rape is further away this year so I'll see whether they go through the same cycle.

[cloddopper]

Being in the Bee Line to their easiest source of nectat or pollen and/or by a gap in a hedge or between building that they use a s a gentler flight path out of the full strength of the wind or so that they fly in a warmer air current is often mistaken for vicious bee's being hell bent  /intent on wiping out the entire human race  .  if the screen does not fix the problem get the keper to resite them
 
Do beware that if some one is permanantly allowed to farm their bees on yoyr land that in england 7 ales that can be construed as ownership of theland unles you challeng them  ( thzt's why private rights of way are coolsed for 2 X 2 number of day per year.

You're also best getting something  in writing in triplicate that says it's your land and he has you permission to site the hive/s in a safe manner & place and that they are responsible for any claims made as a result to the bees being  on your land . These days it only takes a coupe of complaints and your soon finding it's costing you time , money & community friendships to have the bees on your land .

 I was accused of letting my bees swarm by several peoplewho discovered nests in their garages stables out buildings, chimney's & roof voids etc. . . when I went and removed the settled nests I soon realised it was not my bees as all the nests had light Italian queens & stock whereas my bees were all  old British strains of black bees well adapted to the locality .  To prove a point I collected a jar of my big fat black drones and took them along with me in the end .
 On two of th nests I did the old trick of placing a suacer of honey & water about 400 mtrs away and then mover it out to 800 mtrs ..it was not long beforeIi found a bee line heading to a small dense copse on my farming friends land .
 On asking Barry who had their bees on the land he said how did I know . So I told him about being blamed for the feral nestings & how I discovered where the were coming from .
It turned out to be a vicar from Parson Drove some 5 miles away, he'd sited his hives with Barry's permission and had rarely bothered to check them out ...only to come and thieve the honey .

 Barry rang the Vicar there & then and told him to take the bees off his land asap ,the vicar didn't bother over the next three weeks.
 Varroa sorted them out along with 1/4 pint of petrol one cold evening. The old sky fairy  was really amazed that he'd had his permission resinded & even more upset when I took the empty now robbed out hives back to the vicarage for Barry .