An experimental setup in my recent insect behavior class. The students were studying how water temperature impacted respiratory rate in the giant water bug Abedus herberti.

As a lab instructor for an insect behavior class, I use a lot of live insects in my class.  The students enjoy working with them and are generally happy they don’t have to watch videos the entire semester.  Trust me – watching hours and hours and hours of insect behavior video can get really dull really fast.  Live insects are definitely the way to go for a class where most of the students do not have the level of patience that I do.

Unfortunately, the class is held in the spring, so there’s just not many insects out until the end of the semester.  This means that my students work mostly with my favorite insects, the aquatic insects, which is good.  However, it also means that they have a fairly limited variety of things to work with, i.e. things that overwinter as nymphs or adults.  I am able to collect a decent variety of aquatic insects during the winter in Arizona.  Still, there is one lab that would be SO much better if we had a bigger variety of insects to work with: the predator lab.

I developed the predator lab four years ago when my students at the time were constantly begging to put two hungry predators together and watch what happened in the ensuing death match.  (Did I mention that my students are college seniors and grad students and NOT 5 year olds?)  In the interest of turning this morbid curiosity into a teachable experience, the predator lab was born.  In it, I have the students feed several different predators and compare and contrast their feeding behaviors.  They have to watch how the insects capture and devour their prey and describe how they do it in detail.  They also have to tell me whether the insect is a sit and wait predator (they stay in one place and wait for food to swim, walk, or fly by), an active predator (they purposefully hunt down and attack their prey), or something else.  This way, the students get to watch several predators capture prey and eat it, fulfilling their need to promote death and destruction, but they are doing it in some meaningful context.

The predator lab is my favorite.  It requires a lot of work on my part to collect the insects and prepare the containers and prey items for the bugs, but the students get so into the activity that I can’t help but love it.  Even my quietest class, the class I just finished last month, got into it and actually made some noise in class for once!  And things get even better toward the end of the class period when they have finished their work for the day and I let them feed the things that don’t survive well in the lab to my water bugs or to each other.  This is the treat at the end of the semester, their reward for making it through what I consider a very work-intensive course: the death match they’ve been eagerly hoping to set up all semester.  This year there was also a water bug eating a fish to watch (click on the link to see the video!).  That really got the students excited.

Unfortunately, this year was a terrible year for aquatic insects in my part of Arizona.  We got a ton of rain during the winter and there was extensive flooding in the mountain streams that washed out the insects.  The populations didn’t rebound very quickly and there was hardly anything in the streams even several months after the floods.  I was hard pressed to get enough insects for my class this year and we ended up with a measly three types of insects for the predator lab this year: some small predaceous diving beetles, some dragonfly nymphs, and some of the smaller giant water bugs.  It doesn’t take very long to feed a hungry insect, so I brainstormed ideas for activities to fill up half of the class period.  I eventually settled on something I knew the students would love: showing some of the spectacular videos of predatory insects on YouTube.

YouTube is a rather amazing repository of insect behavior data.  A lot of the video is collected by amateurs and many of them know very little about the insects they’ve filmed.  That doesn’t matter – there is some great stuff on there if you know where to look!  For my class, I chose some of the most showy videos I could find.  My students had spent the semester watching live insects.  A video has to be amazing to hold my students’ interest at the end of the semester and the 8 videos I settled on fit the bill well.  And because they are too good not to share, I am posting them here so that everyone who reads my blog can see them too!

Army ants:

Damselfly eating another damselfly – check out the mouthparts moving!:

Preying mantis vs. mouse – and the mantid wins!:

Centipede vs. mouse – and the centipede wins!:

Spider captures and kills a bat:

Antlions (are awesome!):

Orchid mantid captures fly:

I can safely say that this was an excellent way to kill some time in class.  The students loved the videos (there were several collective cries of “Whoa!” during lab that day!) and actually learned something in the process.  A few of them even referenced the videos in their lab write-ups!  It was so successful that I think I will do this again the next time I have an opportunity to teach a behavior class, even if I do have a lot of animals to use in class.  It was great for the students to get to see some things we couldn’t possibly duplicate in class and let them see some more insects in action after their regular lab activities.  It was a great way to finish the last lab of the semester.

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