Ask Dr. Universe: Why do garden spiders hang upside down in the middle of their webs?

Washington State University

Dear Dr. Universe: Why do garden spiders hang upside down in the middle of their webs? – Abree, 10, New Jersey

Dear Abree,

That’s a great observation. Garden spiders and other orb-weaver spiders crawl all around their webs, but we often see their heads pointing down toward the ground.

My friend Todd Murray, an entomologist at Washington State University, told me about a group of scientists who had a question a lot like the one you’ve asked.

These scientists used mathematical models to learn about orb-weaver spiders and how they move around the web. They discovered spiders that wait with their head down for prey can reach prey faster than spiders that wait with their head up for their prey.

While there are exceptions, this position gives spiders an advantage when getting food. Sometimes, prey will hit the top of the web but end up tumbling to the bottom of the web. A spider higher up on the web with its head facing down would be able to see prey below. Gravity also helps spiders as they run down the web.

Murray reminded me how different kinds of spiders can make different webs. Orb weavers tend to make webs in circle shapes. These spiders have parts called spinnerets located in their rear ends, or abdomens, that produce the silk.

Some orb-weavers might create a trap line with their silk, which attaches them to the middle of the web. When an insect hits the web, the trap line vibrates, and the spider can sense dinner has arrived. It might just be a fly, mosquito, moth or wasp.

As fall gets underway, orb weavers eat lots of insects and get bigger. You might identify an orb weaver from its brick red to orange body with white splotches. We see quite a few orb weavers in Western Washington at this time of year. You might notice more spiders and webs in your neighborhood, too.

We are still learning exactly why some spiders build certain kinds of webs. Murray said a wasp in Costa Rica has even revealed how a spider’s web designs can get hacked. The wasp glues an egg on the spider’s abdomen. When the egg hatches, the little larva attaches to the abdomen and starts living off the spider.

“That grub sits there and steals the nutrients from the spider like a vampire does, or a tick, or other blood-sucking creature,” Murray said. “As that grub grows on the spider, the spider does a really amazing thing.”

On the last night of its life, the spider start building a totally new kind of web that looks a bit like a hammock. Once the hammock is made, the spider puts the larvae into the hammock.

“It really does show you how those web-building abilities are hard-wired in the spiders and that they can be manipulated,” he said.

If you keep asking great questions like scientists do, maybe you’ll help us learn even more about the world of arachnids. In

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Toyota Research Institute experiments with robots that hang from the ceiling and unfold to clean the kitchen

Researchers are using fleet learning and simulations to train robots to navigate one of the most complex environments: A home.

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Visiting  private homes in Japan inspired researchers to build a new domestic robot that moves around on the ceiling instead of the floor.

Image: Toyota Research Institute

Working in a factory is easy for robots with the structured environment and repetitive tasks that come with that job. Helping with housework is a much bigger challenge. Scientists at the Toyota Research Institute (TRI) are taking on that challenge by building new domestic robots and training them in a mock home.

Gill Pratt, the CEO of TRI and Kelly Kay, the Institute’s executive vice president and chief finance officer, gave a virtual tour of the TRI labs on Thursday. Max Bajracharya, the vice president of robotics and Steffi Paepcke, the senior user experience leader, explained the research and development process for building these robots. 

The team is prioritizing user experience research, human-centered design, and ikigai–the idea that each person’s life should have deep meaning and purpose. 

The institute’s philosophy is to build robots that take over tasks that have become too difficult for older adults instead of building a one-size-fits-all robot to take over all activities. One prototype is a gantry robot that unfolds from the ceiling to help with household tasks like a bat unfolding its wings. 

The floor model looks like a praying mantis perched on a box. Researchers are using these models to develop capabilities. 

“The robots that you see today are prototypes to accelerate our research, but they are not going to be turned into products any time soon,” Bajracharya said.

Field research for robotics experts

Paepcke said the team used the “genchi genbutsu” research technique which means, “go see for yourself,” to understand how to build domestic robots.

Before the pandemic started, researchers went to private homes in Japan to understand the daily challenges older adults and their caregivers face. Paepcke said that the goal was to understand which tasks people wanted help with as opposed to building a robot that does everything. Paepcke and her colleagues described the goal of their work to amplify human ability and help people continue to do tasks and activities that they find meaningful and enjoyable.

 “A fully automated cooking robot might be physically helpful but emotionally detrimental,” she 

Researchers used the home visits to move the cleaning robot from the floor to the ceiling.  

Bajracharya said that the home visits showed that there was not much floor space available for a robot to move but that the ceiling provided more open real estate.

Researchers used virtual reality (VR) to teach the domestic robots how to clean a surface. A researcher performed the task in virtual reality to show the robot how to complete the task. Another challenge is helping robots understand how to distinguish between different surfaces such as wood, glass, and plastic.

Jeremy Ma, the Institute’s co-lead of the Robotics Fleet Learning Team, said the next challenge is to

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Smart Ways to Hang or Hide Paper Towel Rolls in Your Kitchen

Most of us reach for a roll of paper towels on the regular. Maybe you want to grease a baking pan, or perhaps you need to mop up a small spill—those are just a couple of the hundred or so reasons we might need a sheet or two. But paper towels are not something we want rolling around on the counter, but hiding them under the sink isn’t practical: No one wants to stoop down and dig through the cabinets every time there’s a spill. So, what are some of the best ways to store a roll of paper towels so that the kitchen essentials are on hand but not in the way? We’ve divided possible options into four main types—countertop holders, under-counter hangers, wall-mounted holders, and over-the-cabinet-door holders—so you can find the solution that will work best for your kitchen.



a plate of food on a table: Courtesy of Food52/Rocky Luten


© Provided by Martha Stewart Living
Courtesy of Food52/Rocky Luten



a plate of food on a table: Wrangle your roll so it's easy to grab but not in the way.


© Courtesy of Food52/Rocky Luten
Wrangle your roll so it’s easy to grab but not in the way.

Related: Sustainable Alternatives to Paper Towel

Countertop

When you use a countertop holder, you’re committing to keeping your roll of paper towels in view. Choose a style that echoes the look of your kitchen, whether that means a simple maple wood holder ($48, food52.com), going with a classy gold option ($59, williams-sonoma.com), or bringing home a sleek metal version ($24.99, amazon.com) to suit your more contemporary space. (This style of countertop holder has a tension arm to help you pull just one sheet at a time.). Another option: Repurposing an antique washer plunger or other vintage item to hold your roll.



a close up of a towel hanging on the wall: Courtesy of Schoolhouse


© Provided by Martha Stewart Living
Courtesy of Schoolhouse

Wall Mounted

If you don’t have the counter space or don’t want to add another item to your counters, a wall-mounted paper towel holder is the obvious solution. Look for a holder that will last and is easy to change the roll on, plus easy to use. There are lots of utilitarian options that blend in ($14.99, bedbathandbeyond.com), but there are also sturdy ones that make a statement ($119, schoolhouse.com) all on their own. Some require drilling into the wall to install, but if you’re living in a rental or not ready to commit, you’ll find magnetic paper towel holders ($19.99, containerstore.com) work well, but are generally not as sturdy. You’ll need to be gentle with this iteration. Most wall mounted holders are horizontal but there are some vertical models if that fits your space or style better. For a statement-making wall-mounted paper towel holder, a vintage ice pick setup can’t be beat ($83, etsy.com).



a kitchen with a sink and a mirror: Courtesy of Yamazaki Home


© Provided by Martha Stewart Living
Courtesy of Yamazaki Home

Under Cabinet

A paper towel is always on hand when you have an under-cabinet holder. Styles range from clip on ($32, macys.com) to those that require some installation, often with screws through the base of the shelf or upper cabinet ($13.42, amazon.com). Consider the profile of the holder when you have a

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