Anchor ads are not supported on this page.

4S Ranch Allied Gardens Alpine Baja Balboa Park Bankers Hill Barrio Logan Bay Ho Bay Park Black Mountain Ranch Blossom Valley Bonita Bonsall Borrego Springs Boulevard Campo Cardiff-by-the-Sea Carlsbad Carmel Mountain Carmel Valley Chollas View Chula Vista City College City Heights Clairemont College Area Coronado CSU San Marcos Cuyamaca College Del Cerro Del Mar Descanso Downtown San Diego Eastlake East Village El Cajon Emerald Hills Encanto Encinitas Escondido Fallbrook Fletcher Hills Golden Hill Grant Hill Grantville Grossmont College Guatay Harbor Island Hillcrest Imperial Beach Imperial Valley Jacumba Jamacha-Lomita Jamul Julian Kearny Mesa Kensington La Jolla Lakeside La Mesa Lemon Grove Leucadia Liberty Station Lincoln Acres Lincoln Park Linda Vista Little Italy Logan Heights Mesa College Midway District MiraCosta College Miramar Miramar College Mira Mesa Mission Beach Mission Hills Mission Valley Mountain View Mount Hope Mount Laguna National City Nestor Normal Heights North Park Oak Park Ocean Beach Oceanside Old Town Otay Mesa Pacific Beach Pala Palomar College Palomar Mountain Paradise Hills Pauma Valley Pine Valley Point Loma Point Loma Nazarene Potrero Poway Rainbow Ramona Rancho Bernardo Rancho Penasquitos Rancho San Diego Rancho Santa Fe Rolando San Carlos San Marcos San Onofre Santa Ysabel Santee San Ysidro Scripps Ranch SDSU Serra Mesa Shelltown Shelter Island Sherman Heights Skyline Solana Beach Sorrento Valley Southcrest South Park Southwestern College Spring Valley Stockton Talmadge Temecula Tierrasanta Tijuana UCSD University City University Heights USD Valencia Park Valley Center Vista Warner Springs

What are the differences between indoor and outdoor spiders?

Matmail:

When I see spiders outdoors, they are usually in the middle of a web. Inside my apartment, however, they just stand on my ceiling. Why don't my spiders spin webs indoors? Do they know that my apartment is not a normal bug habitat? Why do they come in here at all? Finally, if they are feeding on (gulp) me, is there even a slim possibility that I will wake up one morning with a web over my bed?

Sponsored
Sponsored

-- Patrick M., Bay Park

Matmail:

I was watching three big night spiders (not their biological name) outside the windows all spinning or repairing webs I had probably disturbed by day and wondered how they were excreting the building materials. Two were going clockwise, the other counterclockwise, so I presumed no hemispherical relationship like weather or bathtub water. Is there some other determining factor like left or right (six) leggedness? A fourth web seen by day high up between two Torrey pines with closest branch tips some 20 feet apart supports a night spider at mid-span. How did he or she span the initial strand?

-- Jeff, Encinitas

Every year at this time the air gets nippy and the big ugly spiders come out. The fat red ones that build webs near your porch light. They're particular favorites of Grandma Alice, who's named the one by the back door Fernando. A big juicy guy who hangs out at night and hides out by day. Jeff's "night spiders" are really garden spiders, which mature in late summer, so we see the adults at this time of year. They're one of the 2000 types of orb weavers that make the common spoke-and-circle webs. And unless they've met with some sort of disaster, Jeff's spiders, of course, have eight legs, not six. Insects have six legs; spiders aren't insects.

Grandma Alice fills us in on how Fernando goes about building a web. First he finds a high spot over the back door and exudes a long piece of silk from one of five abdominal silk-producing orifices, and the wind blows it around until it sticks to something. (Patrick's Torrey pines spiders do the same.) With this in place, he goes about building a frame and three or four radial threads. The rest of the radii are filled in by finding a radial thread at the center of the web, then adding the next thread next to it. He'll add one off to the left, then to the right, then toward the bottom, eventually filling in the whole frame. If you measure the angles formed at the hub, each new radius is nearly uniformly 15 degrees from the one next to it. While Fernando's busy laying down radii, he's also strengthening the hub and the perimeter with circular but non-sticky threads. Spider studiers believe this method of building helps keep the proper tension on the structure.

Between the two non-sticky spirals, the spider lays down the "catching spiral," a thread coated with drops of gluey substance. It stands on a radial thread, feels for the next one with its front legs, then pulls out the sticky thread with its back legs and attaches it to the radius it's standing on. He may proceed to the left or to the right for a while, then reverse direction. Since there are more catching threads at the bottom of the web, spiders don't just go round and round in a circle. The whole process takes about half an hour. For the most part web forms are species-specific, but when the science guys fed spiders caffeine, LSD, mescaline, or amphetamines, the web forms went all to hell. That's one for the "Well, Whaddya Expect?" files, I think.

Patrick's spider housemates might be temporary lodgers, in out of the cold. Or they might be making messy cobwebs (not orb webs) in niches behind bookcases or the refrigerator or ceiling corners. Patrick's place is buggier than he thinks if he has a steady clientele. Spiders have no interest in biting people unless we get in their way.

The latest copy of the Reader

Here's something you might be interested in.
Submit a free classified
or view all
Previous article

Too $hort & DJ Symphony, Peppermint Beach Club, Holidays at the Zoo

Events December 19-December 21, 2024
Next Article

Reader writer Chris Ahrens tells the story of Windansea

The shack is a landmark declaring, “The best break in the area is out there.”

Matmail:

When I see spiders outdoors, they are usually in the middle of a web. Inside my apartment, however, they just stand on my ceiling. Why don't my spiders spin webs indoors? Do they know that my apartment is not a normal bug habitat? Why do they come in here at all? Finally, if they are feeding on (gulp) me, is there even a slim possibility that I will wake up one morning with a web over my bed?

Sponsored
Sponsored

-- Patrick M., Bay Park

Matmail:

I was watching three big night spiders (not their biological name) outside the windows all spinning or repairing webs I had probably disturbed by day and wondered how they were excreting the building materials. Two were going clockwise, the other counterclockwise, so I presumed no hemispherical relationship like weather or bathtub water. Is there some other determining factor like left or right (six) leggedness? A fourth web seen by day high up between two Torrey pines with closest branch tips some 20 feet apart supports a night spider at mid-span. How did he or she span the initial strand?

-- Jeff, Encinitas

Every year at this time the air gets nippy and the big ugly spiders come out. The fat red ones that build webs near your porch light. They're particular favorites of Grandma Alice, who's named the one by the back door Fernando. A big juicy guy who hangs out at night and hides out by day. Jeff's "night spiders" are really garden spiders, which mature in late summer, so we see the adults at this time of year. They're one of the 2000 types of orb weavers that make the common spoke-and-circle webs. And unless they've met with some sort of disaster, Jeff's spiders, of course, have eight legs, not six. Insects have six legs; spiders aren't insects.

Grandma Alice fills us in on how Fernando goes about building a web. First he finds a high spot over the back door and exudes a long piece of silk from one of five abdominal silk-producing orifices, and the wind blows it around until it sticks to something. (Patrick's Torrey pines spiders do the same.) With this in place, he goes about building a frame and three or four radial threads. The rest of the radii are filled in by finding a radial thread at the center of the web, then adding the next thread next to it. He'll add one off to the left, then to the right, then toward the bottom, eventually filling in the whole frame. If you measure the angles formed at the hub, each new radius is nearly uniformly 15 degrees from the one next to it. While Fernando's busy laying down radii, he's also strengthening the hub and the perimeter with circular but non-sticky threads. Spider studiers believe this method of building helps keep the proper tension on the structure.

Between the two non-sticky spirals, the spider lays down the "catching spiral," a thread coated with drops of gluey substance. It stands on a radial thread, feels for the next one with its front legs, then pulls out the sticky thread with its back legs and attaches it to the radius it's standing on. He may proceed to the left or to the right for a while, then reverse direction. Since there are more catching threads at the bottom of the web, spiders don't just go round and round in a circle. The whole process takes about half an hour. For the most part web forms are species-specific, but when the science guys fed spiders caffeine, LSD, mescaline, or amphetamines, the web forms went all to hell. That's one for the "Well, Whaddya Expect?" files, I think.

Patrick's spider housemates might be temporary lodgers, in out of the cold. Or they might be making messy cobwebs (not orb webs) in niches behind bookcases or the refrigerator or ceiling corners. Patrick's place is buggier than he thinks if he has a steady clientele. Spiders have no interest in biting people unless we get in their way.

Comments
Sponsored

The latest copy of the Reader

Here's something you might be interested in.
Submit a free classified
or view all
Previous article

Mary Catherine Swanson wants every San Diego student going to college

Where busing from Southeast San Diego to University City has led
Next Article

San Diego beaches not that nice to dogs

Bacteria and seawater itself not that great
Comments
Ask a Hipster — Advice you didn't know you needed Big Screen — Movie commentary Blurt — Music's inside track Booze News — San Diego spirits Classical Music — Immortal beauty Classifieds — Free and easy Cover Stories — Front-page features Drinks All Around — Bartenders' drink recipes Excerpts — Literary and spiritual excerpts Feast! — Food & drink reviews Feature Stories — Local news & stories Fishing Report — What’s getting hooked from ship and shore From the Archives — Spotlight on the past Golden Dreams — Talk of the town The Gonzo Report — Making the musical scene, or at least reporting from it Letters — Our inbox Movies@Home — Local movie buffs share favorites Movie Reviews — Our critics' picks and pans Musician Interviews — Up close with local artists Neighborhood News from Stringers — Hyperlocal news News Ticker — News & politics Obermeyer — San Diego politics illustrated Outdoors — Weekly changes in flora and fauna Overheard in San Diego — Eavesdropping illustrated Poetry — The old and the new Reader Travel — Travel section built by travelers Reading — The hunt for intellectuals Roam-O-Rama — SoCal's best hiking/biking trails San Diego Beer — Inside San Diego suds SD on the QT — Almost factual news Sheep and Goats — Places of worship Special Issues — The best of Street Style — San Diego streets have style Surf Diego — Real stories from those braving the waves Theater — On stage in San Diego this week Tin Fork — Silver spoon alternative Under the Radar — Matt Potter's undercover work Unforgettable — Long-ago San Diego Unreal Estate — San Diego's priciest pads Your Week — Daily event picks
4S Ranch Allied Gardens Alpine Baja Balboa Park Bankers Hill Barrio Logan Bay Ho Bay Park Black Mountain Ranch Blossom Valley Bonita Bonsall Borrego Springs Boulevard Campo Cardiff-by-the-Sea Carlsbad Carmel Mountain Carmel Valley Chollas View Chula Vista City College City Heights Clairemont College Area Coronado CSU San Marcos Cuyamaca College Del Cerro Del Mar Descanso Downtown San Diego Eastlake East Village El Cajon Emerald Hills Encanto Encinitas Escondido Fallbrook Fletcher Hills Golden Hill Grant Hill Grantville Grossmont College Guatay Harbor Island Hillcrest Imperial Beach Imperial Valley Jacumba Jamacha-Lomita Jamul Julian Kearny Mesa Kensington La Jolla Lakeside La Mesa Lemon Grove Leucadia Liberty Station Lincoln Acres Lincoln Park Linda Vista Little Italy Logan Heights Mesa College Midway District MiraCosta College Miramar Miramar College Mira Mesa Mission Beach Mission Hills Mission Valley Mountain View Mount Hope Mount Laguna National City Nestor Normal Heights North Park Oak Park Ocean Beach Oceanside Old Town Otay Mesa Pacific Beach Pala Palomar College Palomar Mountain Paradise Hills Pauma Valley Pine Valley Point Loma Point Loma Nazarene Potrero Poway Rainbow Ramona Rancho Bernardo Rancho Penasquitos Rancho San Diego Rancho Santa Fe Rolando San Carlos San Marcos San Onofre Santa Ysabel Santee San Ysidro Scripps Ranch SDSU Serra Mesa Shelltown Shelter Island Sherman Heights Skyline Solana Beach Sorrento Valley Southcrest South Park Southwestern College Spring Valley Stockton Talmadge Temecula Tierrasanta Tijuana UCSD University City University Heights USD Valencia Park Valley Center Vista Warner Springs
Close

Anchor ads are not supported on this page.

This Week’s Reader This Week’s Reader