Bees being a little touchy

[Beewildered61]

 I have a nice hive, I found a swarm on the ground on a windy March day, about 2 years ago, and coaxed them right into my hive. They are very robust, always full of brood, bees in and out constantly, and they produced a lot of honey last year.
Well this year, as I was trying to till my garden which is about 50 feet away, one kept buzzing around me and the tiller a few times and fly away, then it come back and kept thumping me on the head, finally it got caught in my hair, I just left the tiller running and walked away shaking my head until she was free. I went back to tilling and she came back, got in my hair again and I couldn't shake her free...walking away, 50-75 feet from the garden, still couldn't shake her loose, took my comb out and quickly flicked it through my hair and her out, she immediately returned and stung me on the hand. I went back to the garden and started tilling again, in a little while here comes another, same thing, thumping me on the head..I was through by then so killed the tiller and no more problem.
Was out in the garden today hoeing, weeding and spreading a little fertilizer, 3 times I heard a bee whizz right over my head, once I felt it slightly graze my hair, but that was all.... I never had any problems like this before. 2 weeks ago, I went as close to the hive entrance as I could go with the riding mower and not so much as a second glance, for 2 hours I was cutting grass right in the area and no bee ever came close to me...
What gives with this? I don't understand the behavior, and I have LOTS more work to do in the garden and don't want to tangle with the girls.. any suggestions?

[don2]

I would re-queen as soon as possible. If they have not swarmed sense you caught them the queen is at least 3 years old, un less she is a super cede queen. My experience from 15 years beekeeping with  an ageing queens comes aggressive workers.  d2

[iddee]

I have found that when weed eating near the hives, the RPM I am running the machine at will decide if they attack or not. I'm guessing it's the vibration. Check the hive to be sure if it is queenrite, then try gardening without the tiller again.
If it continue, like don2 said, requeen.

[Kathyp]

one or two that do that is kind of normal. Seems to me I remember some old and venerable beekeeper advising you kill those that are pesky like that.   

several things can make them more aggressive.  they can need food.  they can be to big and need to be split.  often something has been bothering them and they become very protective of the hive.

you might want to try to eliminate causes before you jump to re-queening especially if you are happy with the queen you have.  you did not get stung, so I would not call their behavior overly aggressive.  they were warning you.  take the hint and suit up when you are working around the hive until you figure out what's going on and solve it.

[don2]

So right Kathyp, I forget to mention that. If they are getting aggravation from something then they are on guard. I have to watch my kitty cat, she likes to perch on top of the hive. d2

[little john]

take the hint and suit up when you are working around the hive until you figure out what's going on and solve it.

Either that, or 'lock 'em in' (assuming each hive has some means of ventilation) the night before working near hives. As it happens, I did exactly this last night, as I'm grass-cutting around several hives this morning.  It's only for a couple of hours, and ensures a sting-free operation. In the past, sometimes they've objected to the mower, and sometimes they haven't ...
LJ