Mason Bee Hell

The mass-produced Mason Bee house

Cheap houses, mass-produced with inferior materials by large companies are a threat to the mason bee and its survival in our gardens. There are various types of Mason bee houses on sale or that you can make for yourself and we outline on the page 'Mason Bee House Comparison' the challenges and benefits of each model, here we examine why it is important to pick the right model. 

Houses with reeds glued in place

The majority of houses you will find in supermarkets, on Amazon, and in large stores will be one piece with the reeds or straws glued into place. These houses can look pretty and have nice designs or shapes but the reality is that the house is a death-trap for the bees. The bees will freely use the house for a year or two, but over time the house will become infected with pests, mites, mold and a build-up of dirt and detritus, The result is the bees will either:-


1. Decline to use the house due to the threat to the cocoons and larvae from the pests and dirt present in the holes.


2. The build up of dirt and pests in the holes means that if the larva in the holes to the front fail to develop into adults, any emerging bees to the back cannot escape, killing them in their place.

3. Mites, mold and disease in the dirty holes from previous occupants severely hinder and prevent any eggs laid from developing into viable cocoons.


The result of these factors means a less productive house for your garden year on year, resulting in fewer bees and less pollination.

It is highly recommended that you do not fall into the commercial trap of buying a house that is glued and fixed in place or you will also suffer the failure of the house in the mid to long term. 

Unsealed Tubes 

A further disadvantage of some mass-produced houses is they are not correctly sealed at the back. Mason bees do not like tubes that are open at both ends. If the tubes are not capped at one end in some way, then the Mason bees recognize that parasites can easily gain entrance and that there will be extra work for them in plugging the hole themselves. Mason bees will always place a plug at the back of the tube with mud but they much prefer a closed tube to start from.

Reeds and Drilled holes with splinters or wood chips

The mason bee seeks and finds a hole of precise dimension and with clean walls. The bee does not like or use holes that have sharp edges that can snag and tear their delicate wings or harm the young larvae. 

Stems blocked at the front

When examining the cheap houses sold commercially you will see that some of the reeds will be blocked at the front or a short way into the tube. The bees will not use these tubes and neither will they remove the blockage. It is wasting valuable the bee's laying time so they will find a more suitable hole somewhere else.  This is another signal that the manufacturers of these mass-produced mason bee houses do not consider the welfare of the mason bees, or indeed know anything about their preferred habitat or lifecycle.

House instructions

When purchasing a house form the stores you will be surprised at how few instructions are provided with the house. If you purchase a good mason bee house from a reputable supplier and you are already aware of the needs of solitary bees (they need a supply of mud or leaves, lots of native plants, etc.), you can still benefit from detailed instructions. There are a lot of clever little tricks that you can use to enhance your experience with the bees. Most of the cheap houses lack such instructions, so you will never fully understand how to place the house in the garden or how to ensure the security of the bees over a long period.

No overhang at front of house

if you purchase a mass-produced mason bee house you will discover they are designed to be as compact as possible so they can be packed and shipped efficiently from the factories. This usually means that they won’t have roofs that protect the nest entrances from water. That’s bad, especially in rainy climates. Moisture causes larvae to rot and can cause kleptoparasitic pollen mites to flourish (that’s bad).

House that attaches to a tree with string or hook

Mason bees do not like excessive movement in their house. The hole should remain as stable as possible. Any movement in the house by the wind or the bending of the tree will lead to the bee abandoning the house and locating a more stable home.  The mason bee will resist trying to land on a moving platform as it wastes time and effort that it would rather use laying eggs and collecting pollen.

House not waterproof

The mason bee does not like moisture or damp in its nesting environment.  Water entry into the house will result in damp cells and larvae getting wet and eventually dying. Your house MUST be placed in a position where it will receive the least rain and the most sun. It is almost impossible for the house not to receive some water but this should be kept to the absolute minimum at all times.

Nests are too shallow or too long

Short tubes or holes will lead to the Mason bee laying only male eggs. The reason this occurs is that the mason bee lays the females furthest away from the hole to protect them. They are not so careful with the males, which they lay near the front. If the house is not deep enough then the female will always be tempted to lay the male eggs thus leading to an overabundance of males to females in the nest.  A nest should be approximately 6″ (15 cm). 

Honey bee shown on house or packaging

This is a concern as it indicates that the manufacturer is not aware of the differences between the species and that they are primarily concerned with profits.