Name_________________
Data Nuggets developed by Michigan State University fellows in the NSF BEACON and GK-12 programs
1
Spiders under the influence
Featured scientists: Chris Hawn from University of Maryland Baltimore County and
Aaron Curry from Baltimore Ecosystem Study LTER
Research Background:
People use pharmaceutical drugs, personal care products, and other chemicals on a
daily basis. For example, we take medicine when we are sick to feel better, and use
perfumes and cologne to make ourselves smell good. After we use these chemicals,
where do they go? Often, they get washed down our drains and end up in local
waterways. Even our trash can contain these harmful chemicals. For example, when
coffee grounds are thrown into the trash, caffeine gets washed into our waterways.
Animals in waterways, like insects, live with these chemicals every day. Many insects
are born and grow in the water, absorbing the drugs over their lifetime. As predators
eat the insects, the chemicals are passed on, working their way through the food web.
For example, spiders living along riverbanks feed off aquatic insects and absorb the
drugs from their prey.
Just as chemicals change
human behavior, they change
spider behavior as well!
Effects of drugs on spiders
have been studied since the
1940s. Dr. Peter Witt first
discovered that chemicals
change spider web
construction. Peter gave
caffeine, and a few other
drugs, to spiders to see if
they would build their webs
during the day instead of at
night, which is when they
usually work. After giving his test spiders some of the drugs, the spiders still created
their webs at night. However, he noticed something unexpected – the web structure of
spiders on drugs was completely different from normal webs. The webs were different
sizes and had more spacing between each thread. Normal webs help spiders to easily
catch prey. Irregularly shaped webs were not good at catching prey because insects
could fly right through the large spaces. After his study, Peter knew that drugs were
bad for spiders.
Drugs significantly impaired spiders’ ability to make webs.
Retrieved from 1995 NASA report.
