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The Great Grow Along

A FREE classroom project uniting the scientific method, biomedical research, and nutrition concepts

Audience:  Grades K-12

Timeline: Minimum of 4 weeks.

This is an ongoing program that can be started any time of the year

The Curriculum:

The Great Grow Along brings together the scientific method, biomedical research, and nutrition concepts in a fun and exciting six-week, educational program. Through an animal feeding project, using live lab rats, students witness the effect of nutrition on growth and are challenged to reflect on their own food behaviors. Students also learn the steps of the scientific method; how to set up a valid scientific experiment, collect data, and analyze the results; and how we can learn about our own bodies by studying animals.

The animal feeding project- that lasts 4 weeks- begins during the second module, after detailed instruction on animal care, the experimental procedure, and nutrition basics have been presented. The project applies the scientific method in the feeding of two rats (additional rats can be ordered). Both rats receive the same food; however, the control rat receives milk and the treatment rat receives a sugar water beverage of equal calories. A switch in beverages occurs in the fourth week of the feeding project. This project will dramatically illustrate effects of nutrition during periods of rapid growth.


  • PSBR provides the curriculum and caging supplies to teachers in PA, DE, NJ and WV.

  • PSBR coordinates the donation of rats from a purpose-bred rodent vendor and we provide cages, water bowls, and food dishes. The project requires the use of female, Sprague Dawley rats that must be obtained from a credible breeding facility to ensure they are disease-free and of known parentage, age, and gender. (These albino rats have a digestive system similar to humans and will eat any food typically eaten by humans). Pet store rats are NOT appropriate for this project.

  • PSBR orders the rats, and the requesting teacher is responsible for picking up the rats at one of the approved locations. These locations can be found below.

  • Bedding: We can offer bedding donations for 2-4 rats. A big thank you to The Andersons Lab Bedding Products and Animal Specialties and Provisions for donating the bedding. This super absorbent bedding offers ammonia control with its sponge-like characteristics that capture ammonia and trap associated odors. This provides a healthier living environment for the rats, and fewer cage changes are needed.

  • Rat enrichment tunnels will be provided for each cage. A big thank you to Animal Specialties and Provisions for donating enrichment items. 

  • Participants are responsible for providing food, bedding (when ordering more than 4 rats), and caring for or adopting out the rats at the end of the study. Adopters must purchase appropriate sized, permanent housing for the rats after the 4 week in-class project is completed. PSBR provides cages for the 4 week feeding project in the classroom, but larger housing for the rats must be provided after the program is complete.

  • PSBR covers the cost of mailing the caging supplies to the participating classrooms. 

  • Classroom speakers are provided upon request. Topics include: basic animal care, how animals help us, biomedical research (including alternatives to using animals) and more.

  • Rats must be adopted out or kept as a classroom pet after the project has been completed. Do NOT release the rats outside.

  • This original curriculum was developed by the Dairy Council of the Upper Midwest.

  • FAQ 

Pick-Up Locations:

Our current rat pick-up locations are located in the following cities:

Hershey, PA; Horsham, PA; Jenkintown, PA; Philadelphia, PA; Pittsburgh, PA; State College, PA; Morgantown, WV; Flemington, NJ; Hampton, NJ; and Frederick, MD. If you would like to use the project, but are not within reasonable driving distance from any of these locations, please contact Lisa Cassaro- This email address is being protected from spambots. You need JavaScript enabled to view it. or 717-731-3559.


Check out our PDF of frequently asked questions about the Great Grow Along to learn more about this project.

Order Forms:

  • Great Grow Along: Order Form - To request rats and/or supplies. Please place your request at least two weeks before you would like to start the project.

  • Indiana State Residents: The American Dairy Association of Indiana no longer sponsors this program for Indiana schools. PSBR has been asked to take over these requests. To request more information and/or to place a rat order, email Lisa Cassaro, PSBR Program Coordinator, at This email address is being protected from spambots. You need JavaScript enabled to view it. or call 717-731-3559


Additional Information:


Great Grow Along Videos:

  • The following videos were created by a 7th grade science class at North East Middle School. "The energy in my classroom has been amazing since the arrival of the rats. The students are so excited to see science in action and practice all the skills they have been taught," said Mrs. Amy Brown, teacher at North East Middle School. Students have thoroughly enjoyed working with the rats and learning about biomedical research and nutrition concepts. "Everyone has been raving about the rats! In the hall you hear, 'I can't wait to get into Science class.' The rats have made Science class an engaging and hands-on experience that has taught us many things including responsibility and actual science happenings," said students Megan B., Nandi P., and Lyndsie H.



PSBR is able to support the Great Grow Along program largely due to the generous support of Animal Specialties and Provisions, The Andersons Lab Bedding, Charles River, and Allentown Inc.

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Lab Bedding logo

Allentown logo 2019 BLUE RGB 300dpi

 charles river logo 


The Great Grow Along in the News:

  • North Rome Christian School in Rome Township participated in the project and were featured in their local newspaper. The article states, "Across the multitude of students who partook in the program, they each related that they enjoyed it, as they received hands-on learning. Students also became attached to the rats and found it easier to learn when “having fun” with the furry critters." View the article here


Current scientific research related to the Great Grow Along:

Animals in the Classroom:

  • New Study Highlights Educational Value of Pets in the Classroom (July 22, 2015): Phase I of "Pets in the Classroom" study by American Humane Association and Pet Care Trust surveys nearly 1,200 North American teachers, reveals that teachers see classroom pets having real educational, leadership and character-building value.

  • Rats are bringing out the best in kids with autism (June 12, 2008): Big, beautiful golden retrievers, gentle greyhounds and incredibly well-trained dogs of all breeds have charmed and comforted children and adults in schools, hospitals and nursing homes for many years. They generally wear vests or collars that identify them as "therapy dogs" as they and their owners volunteer their services in animal assisted therapy programs. The Children's Therapy Center of Washington Hospital in Peters relies on four-legged animals, too, but not the traditional kind...The long, skinny hairless tails are dead give-aways, at least for adults, who know what these therapy pets are -- rats.


Nutrition/Experimental Design:

  • Proteins in Milk Protect Against Cardiovascular Disease in Mice (June 23, 2015): Dietary compounds found in milk-based products lowered cholesterol levels and triglycerides in mice, according to a new study in the Journal of Dairy Science. These compounds also protected against acute pulmonary thromboembolism as well as aspirin, without any of the negative side effects.....During the study, 60 mice were divided into four groups of 15. One group, the negative control, received phosphate buffered saline (PBS). A second group, the positive control, received aspirin. A third group received whey-protein Maillard reaction products (wMRP) formed from whey protein concentrate and sodium caseinate was heated with lactose, and the fourth group received f-MRP, which is wMRP fermented with lactic acid bacteria. The researchers also assessed antioxidant activity and cholesterol reduction effect of fermented cMRP with another group of mice. cMRP is when sodium caseinate reacts wtih Maillard reaction products. The researchers found that the mice on cMRP diets showed lowered cholesteral and triglyceride levels.

  • Here’s what happens to your brain when you give up sugar for Lent (February 18, 2015) By Jordan Gaines Lewis:...Today, with convenience more important than ever in our food selections, it’s almost impossible to come across processed and prepared foods that don’t have added sugars for flavour, preservation, or both....These added sugars are sneaky – and unbeknown to many of us, we’ve become hooked. In ways that drugs of abuse – such as nicotine, cocaine and heroin – hijack the brain’s reward pathway and make users dependent, increasing neuro-chemical and behavioural evidence suggests that sugar is addictive in the same way, too....There are four major components of addiction: bingeing, withdrawal, craving, and cross-sensitisation (the notion that one addictive substance predisposes someone to becoming addicted to another). All of these components have been observed in animal models of addiction – for sugar, as well as drugs of abuse.

  • Sugar Linked to Memory Problems in Adolescent Rats (October 7, 2014): Studying rats as model subjects, scientists found that adolescents were at an increased risk of suffering negative health effects from sugar-sweetened beverage consumption. Adolescent rats that freely consumed large quantities of liquid solutions containing sugar or high-fructose corn syrup (HFCS) in concentrations comparable to popular sugar-sweetened beverages experienced memory problems and brain inflammation, and became pre-diabetic, according to a new study from USC. Neither adult rats fed the sugary drinks nor adolescent rats who did not consume sugar had the same issues. "The brain is especially vulnerable to dietary influences during critical periods of development, like adolescence," said Scott Kanoski, corresponding author of the study and an assistant professor at the USC Dornsife College of Letters, Arts and Sciences.

  • Here's what soda does to young rats' brains (July 30, 2014): Soda is on the mind. A new small study in rats found that drinking sugary beverages may result in memory issues down the line. University of Southern California researchers looked at adult and adolescent rats, and feed them sugary beverages (meant to mimic soda) for a month. After a month, the rats completed tasks that assessed their cognitive function and memory. The adult rats had no problems, but the adolescent rats who had been drinking sugary beverages had impaired memory and trouble learning.

  • Sugary drinks tinker with vital proteins in the brain (Nov. 14, 2013): It is well established that drinking sugar-sweetened drinks is linked to obesity and diabetes, as well as increasing the risk of cardiovascular problems. But the effects of sugar-rich drinks on the brain have received much less attention. These findings come from the first analysis of how sugary drinks affect proteins in the brain. It showed that 20 per cent of the proteins produced in a brain region related to decision-making were altered in rats that drank sugary drinks compared with those given water.


Participating Teacher Feedback

Below are some examples of feedback we have received from teachers who use the Great Grow Along:


Marjorie, High School Biology Teacher - Camp Hill, PA

Student engagement is exceptionally high with this project.  Additionally, there is no better way to learn about the scientific method and research than by participating in it.


Mary, 4th Grade Teacher - Middletown, PA

I use this great program to introduce and use the scientific method. I do it as a whole class Science Experiment to study the parts of the Scientific Method.  We keep a book with all our notes, charts, graphs, and outlines.  The students enjoy handling the rats, measuring their tails, and weighing them.  They also take turns feeding them and keeping them for the weekends. Students look forward to this project every year since I began doing it. The next year, one of the first things I hear is "When are we getting the rats?" I hope that I will always be able to do this project! View notes from some of her 4th graders who participated in the Great Grow Along.


Brintton, High School Animal Science Teacher - Newtown, PA

The reason I continue to use this program is because it is one of the very few opportunities that my students will ever have to see how animals are used in a controlled experiment; where the only variable is sugar water. I tell students that traditionally rats have been used for nutritional studies and think of this as a toddler being raised on soda instead of milk. We run some of the tests on the rats that I was privy to witness at one of your teacher education seminars that you ran several years ago; tests such as the startle reflex, observing behavior for a minute, cat reflex, strength test etc.


Michelle, High School Biology/Applied Science Teacher - Chambersburg, PA

I love the curriculum, and I have adapted it to a high school level.


Todd, High School Agriculture/Biology Teacher - Mechanicsburg, PA

I love this project! It is a great way to teach nutrition, English, experimental design, the scientific method, and animal welfare simultaneously. Not to forget students love the project! Authentic project based learning trains students to use multiple disciplines. Also, this trial appeals to the diverse learning styles in a classroom.


Candy, 2nd Grade Teacher - Carlisle, PA

The Great Grow Along program allowed us to still review what was taught in health, while also reviewing the scientific process we teach at the beginning of the year. We absolutely love this program, and so did the kids! In fact, that was a question I had from parents at Back to School Night this year- Are we doing the rat experiment? I certainly hope that this program has the funding to continue for years to come. It was truly a fun hands-on learning experience for our students. We plan to use it again in the spring.


Donna & Alicia, 3rd Grade Teachers - Souderton, PA 

The nutritional aspect was really a home run; some students were even changing their diets at home and in their school lunches! Parents gave positive feedback to teachers about the changes at home too. The kids just loved it and got so excited when we told them, "Your rats are on their way!"


Deana, 5th Grade Teacher - Defiance, PA

My students and I love doing The Great Grow Along, as many students lack knowledge about proper nutrition. I always have no trouble having student volunteers take the rats after we are finished. I see this program as a way to get students and parents working together and with the school.


Bonnie, 7th Grade Life Science Teacher - Pittsburgh, PA

This is a great opportunity for my students to work with these animals and apply the knowledge to their own nutritional backgrounds.