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Has anyone ever did a rat dissection that lasted more than one period? Our school ordered white rats and all of our teachers only do it for one class period. I wanted to know if anyone does it for more than one period. Also if anyone could weigh in on the pros and cons for doing it one way or another.

Hi Gerry, I know you asked for opinions, so I would like to voice one that I have. I have never done the rat dissection, but I am wondering why a school would spend all that money on the specimens and then just spend one class period doing the dissection. When I had my students dissect frogs, we spent several class periods on it. I am thinking a rat is equally intricate. Carolyn

Hi Gerry, A rat dissection is quite complicated; could you rearrange your schedule and have the students for a long block? I agree with Caroline, rats are expensive and to use them for one period seems wasteful. Perhaps you would consider keeping them for next year?

I remember when I was in high school, we dissected a pig which is much larger than a rat and that also took one class period. I think it's very wasteful to do a dissection lesson for just one period because there are so much information that cannot be processed in just one class period lasting about 2 hours. From a student's perspective, it can be a little difficult to listen to the teacher while focusing and dissecting. I think teachers should make note of that to their administrators or curriculum specialist(s).

I don't know how much kids actually get out of the dissection anyway, but they do enjoy doing them and seeing the different organs and the arrangement of systems in the organism's body.

When my students dissect a fetal pig, we take four to five days--period for each organ system. Students need time to process the information and time to hone their dissection skills.

Hi Everyone - I agree, one class period is much to fast for an in-depth learning experience from a rat dissection. Sometimes we really rush too quickly through content and activities. In my opinion it's much better to give the students time to explore and ask questions. At college level, we spend 3 labs (2 hours each) in Zoology studying rat anatomy. You can go through systems sequentially in layers (external anatomy, skin and muscles first, etc.). It is also helpful to have a rat skeleton and a labeled diagram of the rat skeleton. Might as well get more educational use out of those expensive specimens! Have fun! I'd also encourage you to find one of the many "virtual rat dissection" websites online for those students who are absent and/or students who do not want to do a dissection. This is also good for review for all students. Here is one from Biology Corner - Virtual Rat Dissection http://www.biologycorner.com/worksheets/rat_dissection.html Gerry, if you truly only have one day in your calendar to devote to this activity, I'd consider preparing demo specimens of dissected rats (several stations with different layers of dissection for different body systems). That way they could concentrate on learning the anatomy. Those students who really wish to dissect their own rat could still have that option. Bonus for the teacher - you can document a "differentiated lesson plan" :-) Standard dissection, student observation of teacher prepared specimens or fully virtual dissection. For our high school Biology course, we use frogs for dissection and I spend at least 3 class periods on dissection labs with other class days focused on learning the basic anatomy (before and after dissection labs). We use Virtual Frog software on our high school campus. We use rats and/or fetal pigs for the high school Anatomy & Physiology class. Dorothy

We don't get to dissect any mammals because of cost but we do get to dissect fishes and squids because they are readily available here in Hawaii. I only do the dissection for one period mainly because of the size of the specimens. But if I got to do pigs and rats I would like to think I would take more than one class period so that the students could get the most learning in as possible and the school could get the most for their money. I am just curious...how do you dispose of the rats after you are done? Sometimes we eat our specimens...it just depends on if the students want to or not because I go out and catch them so they are really fresh. That's the perks of living being surrounded by ocean!!

Hi Gerry, Surely, one class period is not enough if it's to be a true learning experience. We spend two days on the frog, and that only after a thorough review of all human body systems and organs. If lab time is limited, it's no time for new instruction - it should be the "aha" moment. We store the specimens overnight in large baggies, labeled by lab team and period, spraying them with a little alcohol/water first. On a lighter note, we also name them (all specimens died of natural causes and had signed a document donating their bodies to make us smart) - that's my story and I'm sticking to it. Don Dean Oakland NJ Schools Project Amazonas Reforestation and Environmental Education http://projectamazonastree.wordpress.com/

Our dissection is 7 days with a full lab practical on day 8 and 9. I really don't believe you can do an effective rat dissection in less than 3 days.

I am teaching a zoology class next year...should have lots of dissections. Would you recommend planning 4-5 days even for something like a worm or grasshopper??

Hi Chris,

It is not necessary to plan that many days to dissect a grasshopper or an earthworm. I tend to schedule 2 days for each of these organisms because they are more simple. One day to 'open up' the specimen and one day to learn the anatomy. On the third day I give a lab practical.

What other animals are you planning to dissect?

You might have a look at Patty McGinnis' squid dissection as you are planning for next year.

It comes down to how much money I get. Probably starfish, grasshoppers, worms, fish, pigs. Squid would be good as well. I've been "promised" 1,000 to order specimens but we'll see. I have really pushed for a course fee in zoology, but the school doesn't want to put course fees on the core subjects, eventhough it is an elective. I got the pigs donated through donorschoose(they were supposed to be for my biology class this year, but did not get funded in time,). And they have grasshoppers and frogs left over from this year...so I might do frogs as well. I'm really interested in how you do your practicals. I would like to do those in this class as well. Is it similar to how my professors in college did it. They put a pin in a structure and you have to identify it?? Should I start a new forum for this topic?

Hey Chris,

We could continue this discussion in the Teaching Zoology forum. Since it is an existing forum, you may see some ideas that may help. Also, maybe we could encourage Dorothy Ginnett to join the discussion. She teaches zoology and is a wealth of information.

How many students will you have in zoology next year?

I remember dissecting a rat in high school biology class. We only spent one class period (2 hour block) doing the dissection. Unfortunately, the teacher had poor classroom management and many students were fooling around so it was difficult to really concentrate and analyze the anatomy.