How to build an insect hotel

Nesting aids for insects – «insect hotels» – are easy to build without much effort or cost: Valuable habitats are created from stones, reeds, clay, wood and other materials. This promotes biodiversity. Once the nesting aids have been built, all that is needed is a little patience until «hotel guests» such as bumblebees, ichneumon wasps and wild bees move into their new home.

At Zoo Zurich, there is a hotel for solitary wild bee species next to the Lori aviary. In spring, it is a hive of activity when new residents move in and lay their eggs in the prepared holes.

Nesting aid for wild bees made from hollow stems

Materials

• Bamboo canes (inner diameter 3–10 mm) or reed mats (available from DIY stores)
• Saw or pruning shears
• Wire
• String
• Possibly a drill
• Possibly perforated bricks

instructions

1. Saw through the bamboo canes behind the knot or cut the reed mat to a length of approx. 30 cm without crushing the stalks.
2. Remove the loose pith in the bamboo with a drill or wire.
3. Tie the bamboo tubes together with the knot at the back or place them individually in the holes of a perforated brick or roll up the narrow reed mats and carefully tie them together.
4. Find a suitable location that is protected from direct weather. Locations facing south-east to south-west are ideal.
5. Attach the bundle or the equipped perforated tile horizontally to a wall or post.

Nesting aid for wild bees made from logs or branches

Materials

• Dry logs or thick branches (e.g. ash or oak)
• Cordless drill
• Drill bits 2–10 mm
• String or wire

instructions

1. Saw the wooden bark into 11–15 cm long pieces.
2. Drill 5–10 cm deep, varying holes (2–10 mm diameter) through the bark from the outside.
3. Clean the holes and sand the entrances smooth.
4. Find a suitable place that is protected from direct weather. Locations facing south-east to south-west are ideal.
5. Attach the perforated pieces of wood horizontally to a wall or post.

Nesting aids for cliff dwellers

The loamy walls of riverbanks can also be recreated. It is best to use sandy loam (or loess) from a building site. You can also buy normal clay and mix it with sand and some sawdust (ratio approx. 1/3). Pour the clay into a suitable box. The resulting «wall» must not be too hard. To help the bees get started, you can also pre-drill a few holes.

Tips for construction

• Drill parallel to the wood grain, i.e. not between the growth rings, but at right angles to them.
• Make sure that the holes are nice and smooth everywhere. Cut stems must not be frayed either. Use sharp drills/scissors to prevent fraying.
• Do not use plastic tubes. This promotes mold growth.
• Do not use bricks. Their holes are far too large. However, you can use bricks as holders for tubes.

Good to know

Not all wild bee species use above-ground nesting aids; almost two thirds of wild bees nest in the ground. It is therefore not possible to save endangered wild bee species by providing nesting opportunities alone. However, the nesting aids offer excellent opportunities for observing nature and help to raise awareness, especially among children.

Sustainable protection of wild bees, especially endangered species, can only be guaranteed through the long-term preservation, maintenance and promotion of natural or near-natural nesting sites and foraging areas. Protecting their habitats is therefore a top priority.