Ever since I added my information to the Michigan Beekeepers Association (MBA) swarm removal map, I periodically get calls from people about bees that have taken up residence at their home. If you have “bees” living at your house, the first thing to do when you notice those buzzing visitors is to determine if they are in fact bees vs wasps. Michigan State University (MSU) has a great resource to help distinguish bee nests from wasp nests. If you determine that your visitors are wasps, and they are occupying a place that would put them in regular contact with you or your family, you may want to seek help from a professional to remove them, as wasp and hornets can be quite defensive. In contrast, bees, of which there are at least 450 varieties in Michigan, are generally less likely to sting. Most of them live alone or in small colonies, and are not generally defensive. So, for the most part, you can safely leave them be. In fact, since bees are vital pollinators, you may even want to help protect them by providing good places for them to live. You can find information about creating bee habitats from Michigan State University.
That said, there are some bees you probably don’t want living in your house. Carpenter bees are one example. They can cause wood damage if they nest in your home. Honey bees are another. Honey bees are unique among bees in that they form very large colonies (sometimes more than 50,000 bees), which home owners may hear buzzing when they take up residence in a house. They store large quantities of honey, which can cause damage to walls and ceilings, should it get too hot or ferment and start to drip. And when their colony feels threatened they can become defensive.
Because my callers have generally found my name at the Michigan Beekeepers Association website, which provides information for identifying bees vs wasps, the folks I have talked to often have already determined that their visitors are bees (fuzzy, and/or carrying pollen). So it is not surprising that the question I get asked most often when I am called about resident bees is “are these honey bees?”.
Honey bees are usually around 1/2 and 2/3 of an inch long. To put that in perspective, a dime is about 2/3 of an inch across. Worker honey bees have pointed abdomens (back end), are kind of furry, have strips, and although there are variations in shade, they are brown/black and a muted yellow in color. They carry pollen on their back legs, and if you see bright yellow on a honey bee, it is likely pollen, not the bee itself.
If you run across a large cluster of bees, sitting out in the open, with no “nest” in sight, that is what is known as a swarm, and it is unique to honey bees.
Those bees are hanging out while they look for a new home. They will almost certainly find a place to live and move on in the next few hours or days. But while they are with you, you may be able to accelerate their departure by finding a beekeeper to collect and rehome them.
The identification challenge comes when the bees are flying in and out of an opening of some kind. Both bees and wasps do that. And while they are coming and going, they can be hard to get a good look at! Since most of us are carrying digital cameras (cell phones) with us these days, you may find that taking a couple of pictures is helpful for getting a better look. Plus, if you end up calling for help with identification, having a picture to share is very useful. If you can confirm that your visitors are fuzzy, and/or carrying pollen, they are bees, but are they honey bees? If they are, to remove a colony from a structure without killing all the bees, you will likely need the help of a professional who does what we call “cut outs”. Unfortunately, finding individuals who provide that service can be challenging, and removal can be costly. So before you go looking, maybe we can help you determine if your bees are honeybees (or carpenter bees, or something else).
One clue may be what the bees are flying in and out of. Honey bees do not live in the ground, so bees flying in and out of a hole in the ground are not honey bees. Also since honey bees live in large colonies, they will be seen at holes that could potentially give them access to a fairly large space, usually equivalent to a couple of gallons or more. When they are found in houses, it is often inside a wall or soffit, or in a chimney. And on a warm, dry day, there should be many bees coming and going. If you are just seeing occasional bees entering and leaving, or the bees are going in and out of an opening in patio furniture or other structures where they can access only a limited space, it is unlikely that you have honeybees in residence
So, if they are not honey bees, what are they? Fortunately, most of the other bees that you might see flying in and out of a hole in your house are tunnel-nesting, solitary bees, and all are unlikely to sting you if you don’t disturb them. But you may still want to know what they are. In addition to where they live, their size, color and how they carry pollen can provide clues. Let me introduce you to the four most likely candidates, carpenter bees, leaf cutter bees, mason bees and bumble bees.
Carpenter bees: The most common carpenter bee in Michigan is large and resembles the closely related yellow and black bumble bees we have here. Both have hairy midbodies. However, carpenter bees have a shiny, black, hairless abdomen (the back part of the bee) whereas the abdomen of bumble bees is covered with black and yellow hairs. Carpenter bees create tunnels in wood in which to lay their babies. The tunnel created by the boring bee is so perfectly round it appears to have been drilled by a tool. Although their native nest of choice would be an old tree, carpenter bees can be serious, wood-destroying insects if they choose to build their nests in your home. Carpenter bees seem to prefer softwoods like cedar, redwood and clear pines used in window trim, screens, soffits and fascia boards and decks.
Leafcutter Bees: Leafcutter bees get their name because they cut off pieces of leaves and carry them home to use in their bee nurseries. Like the carpenter bee, leaf cutter bees raise their offspring in tunnels/tubes, but unlike the carpenter bee, they do not cut tunnels into wood. Rather, they use preexisting tubular spaces. These cavities could be in hollow stems, rotting wood, empty tunnels left by beetles, as well as manmade holes and tubes. Leafcutter bees hatch in the summer, and that is when you will see them building their nurseries. Leafcutter bees are similar in size to honeybees (midsize). The leafcutter has a larger head than most bees due to extra muscles they have developed to help them chew through leaves. An interesting difference between leafcutters and honey bees is that leafcutters carry pollen on the underside of their abdomen rather than on their legs like most other bees. This creates bright yellow/gold colored bee butts that are distinct to leafcutter bees and easy to spot.
Mason Bees: Often called orchard bees or blue orchard bees, mason bees are smaller than honey bees, and often have metallic green or blue backs. They get their name because they use mud to create nests for their babies inside tunnels or reeds. Like the leafcutter bees, they do not make their own tunnels, but use preexisting tubular cavities. They are most active in spring, and are able to fly at cooler temperatures compared to honeybees. They have a reputation for being amazing pollinators, especially for fruit trees, that often start to flower when it is still too cool for honeybees to be out and about.
Bumble bees: Bumble bees are larger than honey bees and are very hairy. They are most often black and yellow in color (but can have orange or white as well), and in contrast to carpenter bees, who can look very similar, have a furry abdomen (back end). Unlike some of the other bees listed here, bumble bees are not solitary bees, and nest in colonies like honey bees. But unlike honey bees, their colonies are small, with most bumble bees living in colonies of less than 200 bees. In nature, bumble bees build their nests in quiet, shady locations such as old rodent burrows, under leaf piles, and in logs, but you may find their nests in manmade structures like a wood pile, bird house, attic insulation, or even the batting of old furniture cushions. Bumble bees are active throughout the spring and summer, and are excellent pollinators of many wildflowers and an assortment of crops including cucumbers, peppers, tomatoes, strawberries, blueberries, raspberries, melons and squash.
I hope this has helped you identify your bee. If you are still unsure of what your resident bee is, MSU has experts who can help you. You can reach MSU through its Ask Extension form.