Bees going into my masonry

[Dexterwolf]

Hello first time poster so go easy. I have seen bees go in and out of various holes in my mortar of my house. They are definitely bees there are not loads coming out or going on but I am concerned about my house wall and mortar. Are they dangerous to me and my home foundation and will they go and come back next year.

[gavin]

Hello first time poster so go easy. I have seen bees go in and out of various holes in my mortar of my house. They are definitely bees there are not loads coming out or going on but I am concerned about my house wall and mortar. Are they dangerous to me and my home foundation and will they go and come back next year.

Bees going in and out of holes in mortar at this time of year are very likely to be red mason bees. There is some discussion and pictures of them here:

http://www.sbai.org.uk/sbai_forum/showthread.php?500-Red-mason-bees

They may clear out pre-existing holes but then they strengthen them with mud walls when they complete their nests. You'll see them in April and May while they fly, mate, and provision their nests with pollen then for the rest of the year the larvae and pupae will slowly develop unseen. No stings, no risk to people. If you have any fruit trees they are excellent pollinators.

Stingless, non-threatening pollinators - every home should have them!

[busybeephilip]

Dangerous to you - NO but they will sting you if you try to catch one in your hands !

Damage your house - They will use a nesting tunnel that is about 1 inch long. thats about the depth that you would rake out of your brickwork to carry out repointing so dont worry your house is not going to fall down.

But, the fact that you have these bees implies that your mortor might be in in some state of decay as these bees will only burrow into a soft medium. You are likely to have the old lime mortor as opposed to portland cement that is rock hard and they are unlikely to burrow into this substrate, so your property is probably of some age. If you are considering repointing I would use the same as the existing mortor, lime mortor allows some movement and moisture evaporation to occour whereas portland cement will crack on movement and tends to prevent water evaporation so if you use the wrong mortor you might end up with damp walls.

Wait until the end of summer to do any repointing, this lets the bees finish their life cycle and helps the environment.

Yes, they will return next season and use the same holes

TIP : By the way to test your mortor use vinegar, lime motor will fizz and produce some bubbles esp with any white bits in the mortor, portland will not react to vinegar ..

[Adam]

Bees going into various holes would indicate mason bees rather than honeybees who would generally use one entrance. They (masons) DO like soft bricks and mortar. Very good to watch when sitting outside an old pub. :)

Nice photos in your link, Gavin.
.
.
.
.
.
.
And who would ever try to catch them in their hands?

[busybeephilip]

And who would ever try to catch them in their hands?

Some who thinks they are invincible

[gavin]

Thanks Adam :-)

Do they really sting or do they bite when cornered? Even honeybees can give you a nip and these critters are adapted for clearing burrows.



Wait until the end of summer to do any repointing, this lets the bees finish their life cycle and helps the environment.


If you do that you destroy the next generation which pupate in their tunnels and emerge next spring. Do it in late April and the adults will be out but any start on nesting again not properly underway.

[busybeephilip]

Ta Adam : I stand corrected !

It appears then there is just a small window to get any building work done should that be needed.