Reservations please: insect hotels for overwintering friends

Fiann Ó Nualláin discusses the work of our insect friends in the garden and suggests a seasonal B&B.

The temperature is dropping steadily each day and we are fast approaching hibernation time for several garden visitors who have, for the past number of months, called our garden their food bank, if not their home.

Some take their chances deep in the hedge or nestled under the ivy, but many will remain snug in a hideaway crack in an old wall, burrowed into the ground or snuck into a corner of the shed.

You can offer them some real hospitality and make or buy a nice des res insect hotel. The benefit of an insect hotel is that the creatures won’t be disturbed as you tidy the garden or root around the shed — they will have a safe and secure place to bed down over the winter and that will help more survive until spring — and get a new batch of pollinators and pest controllers on the go.

Not every insect hibernates as adults, some lay their larva, die off and the larva overwinters until next spring and emerges as a new generation but some do the full-on adult hibernation.

Those that do have a very clever trick up their sleeve — they slowly begin to alter their biochemistry over autumn in order to produce more glycerol which actually helps lower the freezing point of their blood.

Yeah – they make their own antifreeze. Gotta love nature.

So anti-freeze’d up or not, they still need shelter to get out of the extremes — and we’ve had them already — they will already be investigating bolt holes now.

So it’s very timely to make some makeshift shelter with a bundle of twigs tied together and secured to a tree, or eaves in a shed.

Or you can place out for them, a really attractive (to them) and aesthetic (to your garden), purpose-built hotel.

You can easily make one up from upcycled items and a few minutes of awe and envy on Pinterest, or you can buy kits and ready-mades in your local garden centre.

Before we shop or knock up a DIY one, let’s look at the potential guests.

That way, we can get the rooms right.


When it comes to Bumblebees they are burrowers, not checkers-in — the queens venture underground, tunnelling around 10cm below ground level and totally ignores log piles and hotels. But solitary bees will appreciate the option of a hotel stay — some are ground nesters but many are wood nesters, so a wooden box, biscuit tin or homemade construction filled with twigs, drill-holed wooden off cuts, hollow bamboo canes and the like, will really work for them.

The solitary bees do a lot for our gardens and native flora too and while everybody was jumping on the bandwagon of saving the honey bee and the honey industry, these guys were the ones visiting your flowers without celebrity endorsement or facebook likes.

The solitaries like chambers to rest, nest and breed in — so hollow bamboo in the mix with wide bore drill-hole wood is ideal.

Place their insect hotel in full sun with an eye to be also sheltered from harsh rain penetrating the compartments — a roof tile on top often does that trick.


Most of our native butterfly species have evolved to spend Irish winter in their larval stage, but there are a few that can and chose to hibernate as adults.

In particular the brimstone, comma, peacock, small tortoiseshell and red admiral species.

They have a tendency to hibernate in outdoor structures such as sheds and farm buildings, so are easily adaptable to a hotel.

The best types are boxy ones with some room to manoeuvre inside. You can adapt a bird box or a post box.

They prefer the covered front to have vertical slit entrance points.

Butterflies are notoriously fussy — expect a bad trip advisor score — but a trick to get them to investigate in the first place is to place some mashed banana or overripe pear in a compartment of the hotel or smeared onto one of the entrance point, as the aroma and food supply is a great incentive to hang about and nosey-in.


Ladybirds love a good log pile, but also love a nice resort.

They naturally like cracks and crevices so those hotels with slate and old bricks in the mix are ideal.

Some prefer to burrow into bark so add some vertical logs, rather then cut-end stacks. The great thing with ladybirds is that you only need to get one to like the place and they put out the good word – actually they excrete a pheromone around the vicinity of any recommended location and this attracts family and friends to come stay nearby too.

The best hotels like the best people, should have good accommodation of diversity.

No, I’m not running for Mayor – but you will get spiders and earwigs too, so be open to it. If your hotel is ground-standing then you may also find it filling up with


hibernating beetles — most are burrowers, but some are opportunistic. Remember these guys are beneficial insects too, killing several pest species and moving leaf litter into soil to help it decay while adding and add humus.

You can make standalone hotels, designed to individual hibernators and that’s great, but if you make a multistory with various compartments, you will get the beneficial insect quota up year-after-year. And it looks so cool.

You can even green roof it with sedums or other nectar-rich plants.

Multi stack pallet hotel

Start with a pallet stack. It can be halved or even quartered pallets, depending on your garden size.

If you are a balcony gardener then a vertical pallet can be converted too.

The pallets have ready gaps to be filled with twigs, straw, cones, wood cuts, logs and fire kindling sticks, bricks, old terracotta plant pots even upcycled wine or beer bottles. The more levels, the more visually impressive, but also the more accommodation offered to your guests.

The kaleidoscope of materials makes it look funky but also delivers many different investigating and nesting options.

The mix of materials will suit many different insects; I often use garden soil as a mortar to hold everything in and even create plant pockets too as a buffet and a nectar bar as well, for aesthetic purposes.

The wedge blocks that make up pallet spaces can be drilled with various sizes of bit to invite the various-sized chamber dwellers. You can clad the roof with tiles or felt or even green roof it.

Most of the species mentioned will take to a good log pile as well — but I will save the expert tip on that construction for next week.

Seeing as it’s almost Halloween, next week we will continue helping the hibernation party with a look at treats and tricks for bats, warty toads and spiny creatures. Wooohooahhh!


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