Hate Housework? Try A Slug

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: Good housekeeping

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:

: Hate housework? Can't find a reliable cleaner?

: Try a slug

:

: IT WASN'T just the pink-and-grey colour scheme.

: Or even the loose tiles. The thing that Martyn

: hated most about his bathroom was the

: mould. Dark spots speckled the grout and a fuzzy,

: grey film clung to the shower curtain. No sooner

: had he scrubbed it off, back it came. " It was

: Mould City, " says , a naturalist at the

: Australian Museum in Sydney.

:

: Hardly surprising, really. and his partner

: Lynne McNairn had chosen to live in an old,

: two-storey, brick-and-fibro house in Narraweena, a

: soggy suburb to the north of Sydney. The bedrock

: is so close to the surface that when it rains, water

: oozes out of the ground and turns the garden into

: a bog. Damp comes with the territory, and in a

: poorly ventilated bathroom, mould was inevitable.

: It was one long battle against the fuzzy fungus

: until, one day, decided to take on

: domestic help. He started with one, then three,

: and eventually a whole army of cleaners. They

: were small, cost only bed and board, and didn't

: use nasty chemicals around the house. They were

: slugs: a motley crew of striped ones, red ones and

: big, fat grey ones.

:

: As a naturalist, is keen to experiment

: with biological controls of all sorts. Since he

: settled in Narraweena, he has offered houseroom

: to a whole menagerie of creatures in return for

: their doing a few chores. His ultimate aim is to

: build up a trouble-free staff of animals that can

: be left alone to get on with the job. Already, he

: has turned up previously hidden talents among

: some of the local fauna.

:

: The slugs were his first employees. " Some slugs

: love mould. They thrive on it, " says . " I

: noticed a few came into the house and headed for

: the bathroom. A friend of mine had seen slugs

: eating mould in his house so I thought I'd test it

: out. " Worried that the molluscs would never make

: it across the vast expanse of carpet that lay

: between them and the bathroom, he gathered

: them up and carried them to their new home. " Lo

: and behold, it worked. They kept the mould down.

: They didn't get rid of it completely but we only

: needed to do a little work. They are particularly

: good at cleaning grout, silicone sealer and other

: hard-to-reach places, " he says.

:

: Slugs have a strong homing instinct, foraging in

: the damp night air and spending the deadly

: desiccating daylight hours in a cool, moist retreat.

: provided his new staff with comfortable

: lodgings in the shape of a little ceramic pot

: perforated with stars and crescent moons--the

: sort more usually used to waft perfumed oils

: around the place. " They soon learnt that was

: home, " he says. Each night, the slugs crawled out

: of the moons and stars and slithered off on their

: fungal foray. At daybreak, they crept home where

: they were safe from bare feet and torrents of hot

: water. In the breeding season, the slugs took a

: break from housework, heading down the drain

: and out of the vent pipe to seek a mate in the

: garden. After a brief romantic interlude, some

: came back, unable to resist 's

: increasingly furry shower curtain. Those that failed

: to return were replaced with new recruits from the

: garden.

:

: Since he took on his first few slugs, has

: tried out several species, hoping to find the

: perfect home help. The leopard slug is a good

: mould-grazer, but tends to slip out of the

: bathroom at night to explore the house. " You

: might step on it during its nightly wanderings, so

: it wasn't ideal, " says . The little striped

: slug--not so little at 3 to 5 centimetres long--was

: better. It has a healthy appetite for mould and

: goes about the job as energetically as a slug can.

: The red triangle slug, which can grow up to 10

: centimetres, was a bit too picky. " It will eat

: mould but it won't go on the ground. It's good for

: shower curtains but won't clean the other parts of

: the bathroom. " The best slug for the job turned

: out to be Limax flava, the much-maligned great

: grey slug familiar in European gardens and

: introduced to Australia. L. flava is a big, beefy

: slug, 9 centimetres at full stretch, so it eats a lot

: of mould. But it's also pretty sluggish, for want of

: a better word, and doesn't wander far at night, so

: there's little risk of finding one squashed into the

: carpet the next morning.

:

: At one point, great

: greys, stripys and a

: young red triangle

: shared the workload and

: was more than

: happy with their efforts.

: They were efficient and

: didn't stain the carpets

: as cleaning with bleach

: did. Eventually, though, it was time for a new

: bathroom: that pink-and-grey just had to go.

: Freshly plumbed and neatly tiled in green and

: white, the new bathroom is airy and bright. The

: old plastic shower curtain has gone, replaced by a

: shiny, glass cubicle. " We do have a silicone strip

: around the shower tray which is hard to clean and

: the slugs do that brilliantly, " says .

:

: Even so, redundancies loomed. It was time to

: downsize the staff. The celestial slug house has

: gone, and the slimmed-down workforce consists of

: three small stripy slugs. " They are small enough

: to fit in the groove of the sliding door without

: getting squashed, " says . " Occasionally

: they get fed up and crawl down the plughole, but

: generally they do a good job. "

:

: has been well and truly bitten by the

: slug bug and hopes other people will give them a

: try. " It's an alternative for those who can't be

: bothered scrubbing or who don't like chemicals, "

: he says. " They don't remove all the mould, but

: they do keep it down to an acceptable level. " For

: those who don't fancy the sight of fat grey slugs

: in the bath, he is working on a range of designer

: slugs in fetching bathroom colours. L. flava varies

: naturally from grey to yellow, and also comes in

: albino. " The yellow form is quite attractive, " says

: . " And the white ones can be tinted by

: feeding them vegetable dyes--although you have

: to keep this up or they revert to white again. "

:

: Apart from the odd silvery trail up the bathroom

: wall and a few droppings that are easily swilled

: away during the morning shower, slugs don't have

: any real drawbacks--unless you collect vintage

: wines. " They like the mouldy labels, " warns

: . " They eat them, and then you don't

: know what's in the bottle. "

:

: With Sydney's warm, damp climate--and especially

: on 's boggy patch of land--there's plenty

: of work for a large household staff. Keeping down

: cockroaches, for instance. Roaches come in all

: sizes, from the thumb-sized Periplaneta species

: to the smaller but more persistent Blattella

: germanica. " They're a problem--for other people, "

: says . His house is so well protected, he

: sees about one cockroach a month. The first line

: of defence is a colony of leaf-tailed

: geckos--prickly-looking lizards with flat,

: leaf-shaped tails. These particular geckos don't

: have sticky feet and can only cling by their claws

: to rough surfaces. They live outside on the

: brickwork, where they are active at night. " They

: form a sort of moat of geckos that insects have to

: get past before they can make it into the house, "

: says .

:

: Any that do get in risk an encounter with the

: " lounge lizards " , secretive skinks that skulk by day

: behind the lounge (that's a sofa to non-Australian

: speakers). The skinks emerge in the evening to

: hunt a whole range of unwelcome guests,

: including cockroaches, spiders and silverfish. " You

: hardly notice they are there. But they'll eat

: anything that's moving on the ground, " says

: .

:

: Cockroaches might be unpleasant, but termites

: are a householder's worst nightmare. Given half a

: chance, they'll eat the house--unless something

: eats them first. In Narraweena, termites have a

: natural enemy in the little black ant. If the ants

: come across a band of termite workers, they'll

: follow them down into their galleries where they'll

: eat termites at every stage of development from

: egg to adult. Above ground, any termite king or

: queen setting out to found a new nest is fair

: game. If they land anywhere near the ants they're

: done for--and that's one fewer nest to worry

: about. and McNairn are happy to share

: their home with a few black ants in exchange for a

: termite-free house, although the ants themselves

: can become a nuisance. " They'll eat our food

: too--from the sugar to breakfast cereals--and they

: get everywhere. You might find them living in the

: teapot, for instance. But we tolerate them. They

: patrol the places a human cleaner can't get to, "

: says .

:

: Scuttling insects and stationary eggs are relatively

: easy to deal with, but in Australia it's hard to

: avoid flying insects, especially mosquitoes. Most

: people keep them out with wire screens.

: 's insect screens are woven from silk and

: tailor-made by orb spiders. Webs on either side of

: the ramp leading to the first-floor entrance create

: an insect-screened corridor to the house. Golden

: orb spiders are best for this job. They build fairly

: permanent webs, and although they don't always

: build them in the right place or at the right angle,

: the webs can be moved into position by carefully

: detaching the supporting strands and fastening

: them to a more suitable twig or stem. Garden orb

: spiders do their bit too, but they have a serious

: drawback--they build a new web each night,

: eating the old one the following morning. " This

: means we sometimes walk straight into a web at

: night that wasn't there during the day, " says

: .

:

: There are plenty of pests left to keep a whole

: range of wildlife fed, from dragonflies to bats, to

: fish and frogs which live in the garden's pools and

: ponds, even insect-eating sundews and pitcher

: plants, which thrive on the boggy ground. And

: about this time of year, the anti-mosquito task

: force is swelled by the arrival of several species of

: Toxorhynchites--unusually large mosquitoes with

: glittering iridescent bodies and wings. There are

: dozens of species of Toxorhynchites around the

: world and they share one endearing habit: as

: larvae they have a voracious appetite for the

: young of other mosquitoes. The adult insects suck

: plant sap and nectar, not blood, and they lay their

: eggs in small pools, containers filled with

: rainwater, tree holes and even waterlogged

: footprints in the lawn. The offspring of other

: mosquitoes don't have much of a chance. A single

: Toxorhynchites larva can eat its way through 400

: smaller mosquito larvae before it reaches

: adulthood. " Although we've still got plenty of

: mosquitoes, there are fewer than there might

: have been, " says .

:

: Apart from their battery of biological controls,

: and McNairn restrict their fight against

: pests to mechanical methods--squashing snails,

: for instance--or at most, sloshing ecologically

: friendly soapy water over bad infestations of scale

: insects. The result is a garden filled with native

: species, from mud-burrowing spiny crayfish to

: seven species of insect-eating lizard. Native

: honeybees, rescued from a fallen tree, nest in two

: hives that has provided, each potentially

: giving him a litre of lemony-tasting honey a year.

: Native wasps have moved into other artificial nest

: sites--and keep down harmful caterpillars. " We

: provide what the animals want, and they come, "

: says . " And the more diversity there is,

: the less likely we are to have pests. Pests may

: get used to chemicals, but they never get used to

: being eaten. "

:

: And there's a bonus. There's always a ready

: supply of new additions to the household staff.

: " We'll probably never have a scrupulously clean

: and tidy house but we have one that's

: comfortable, entertaining and doesn't give us too

: much work. "

:

: For anyone thinking of following 's

: example, it's probably best to check that it's OK

: with any other humans living in the house.

: Fortunately, McNairn shares 's

: enthusiasm. " I like having the critters around, "

: she says. " They make our life interesting, and

: generally you don't even know they are there.

: They just quietly get on with their jobs and every

: now and then you see one of the geckos or slugs

: and think, that's nice, they're still here. "

:

: Unless they are spiders, that is. " There was a bit

: of a problem when a large banded huntsman

: spider I'd introduced to the garden took up

: residence in a drawer, " admits . " When

: Lynne went to take out her favourite grey jumper,

: part of it moved under her hand, " he recalls. Her

: piercing scream persuaded him to put the spider

: at the farthest part of the garden. " It never

: returned, " he says, " probably because its sound

: receptors are still ringing. "

:

: Pain

:

: From New Scientist magazine, 29 July 2000

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