About the Course

Backyard Habitats

  • Grades 3-4
  • CTY-Level
  • LIVE

What creatures live around you, and how can you tell? How does gardening or mowing the lawn affect local animals and plants? What happens to bathtub water after it goes down the drain? Explore your neighborhood’s ecosystem through the lens of an environmental scientist.

Using dichotomous keys and other classification processes, identify various flora- and fauna-like grasses, insects, and birds. Create environmental drawings while applying the mathematics of scale to your surroundings. With attention to watersheds, runoff, and waste treatment, trace rain’s gradual journey to the ocean.

Through these activities, acquire an understanding of people’s roles in their local ecosystems, investigating related topics like native plants, invasive species, and pollinators. You and your peers gain a hands-on introduction to basic ecology and environmental science through local yards, parks, sidewalks, parking lots, and green spaces.

Fall, Winter, and Spring Time Commitment: 4-5 hours per week (1 hour class time, 3-4 hours independent work).
Summer Time Commitment: 12-15 hours per week (3 hours class time, 9-12 hours independent work).

Important Dates
Apply by August 30 to start:

Apply by August 30 to start:


Register for an Online course by selecting an open class below. If no open classes are listed, then course enrollment is currently closed. Note: You will need to have an active CTY Account to complete registration through MyCTY.
Synchronous class meetings typically last about an hour.


This course is not open for enrollment at this time. Please check back later.

Testing and Prerequisites

  Math Verbal
Required Level CTY-Level or CTY-Level
Check your eligibility using existing test scores If you do not have existing test scores:

Students must achieve qualifying scores on an advanced assessment to be eligible for CTY programs. If you don’t have qualifying scores, you have several different testing options. We’ll help you find the right option for your situation.

Sign up for Testing Learn More

Cost and Financial Aid

  • Tuition
    • Varies
  • Application fee
    • Nonrefundable Application Fee - $15 (Waived for financial aid applicants)
    • Nonrefundable International Fee - $20 (outside US only)

Financial Aid is available

We are committed to serving all talented youth regardless of financial circumstances. Financial assistance is available based on need.

Learn More

Course Materials

Please acquire all course materials by the course start date. If you have questions about these materials or difficulty locating them, please contact ctyinfo@jhu.edu.

Book Title: Everything You Need to Ace Science in One Big Fat Notebook
Author: Workman Publishing, Michael Geisen (Editor)
ISBN: 978-0761160953

  • Standard school supplies
  • 2-liter plastic bottles, empty and clean with their lids (two are needed; 1-liter bottles can be substituted)
  • Activated charcoal (optional)
  • Bowl or large plastic re-sealable bag (Zip-loc style)
  • Cardboard, 10” × 6” (25 cm × 15 cm)
  • Coffee filter, large enough to cover a quart/liter size jar
  • Colored pencils or crayons
  • Compass (A free cell phone compass app can be used.)
  • Felt tip pen/Sharpie marker, black or dark-colored• Fork or tongs (Any long item that fits inside a quart/liter size jar will work.)
  • Grass seed or bird seed, 1/8-14 cup (~16-40 grams)
  • Hand lens (optional)
  • Masking tape (Duct tape or electrical tape can be used.)
  • Newspaper (Other coverings for the work area can be used.)
  • Newspaper or construction paper, several sheets
  • Notebook
  • Quart/liter glass/plastic Mason jar (or similar jar), one is needed (A recycled jar can be used.)
  • Packet of flower or vegetable seeds, any kind
  • Pebbles, enough to cover the bottom of a quart/liter size jar
  • Photo-taking device (A digital camera, mobile phone, or tablet will work.)
  • Plastic cups, 8-12 oz. (237-296 mL), two are needed (Recycled cups can be used.)
  • Potting mix/soil, small to medium bag
  • Small plant or moss
  • Spoon
  • Spray mister/bottle (optional)
  • String, ~40 cm (Yarn can be used.)

Technical Requirements

This course requires a computer with high-speed Internet access and an up-to-date web browser such as Chrome or Firefox. You must be able to communicate with the instructor via email. Visit the Technical Requirements and Support page for more details.

This course uses a virtual classroom for instructor-student communication. The classroom works on standard computers with the Zoom desktop client, and on tablets or handhelds that support the Zoom Mobile app. Recorded meetings can only be viewed on a computer with the Zoom desktop client installed. The Zoom desktop client and Zoom Mobile App are both free to download.

Terms & Conditions

Students may interact in online classrooms and meetings that include peers, instructors, and occasional special guests.

Courses may include videos from the web. Recommendations or links at the end of videos are provided by the video host and are not CTY recommendations. 

You may have the option to post your work on public third-party sites (e.g., YouTube). 

Virtual class meetings may be recorded for students to review.

After a you complete a course, your projects may be used to illustrate work for future students. 

About Science and Engineering at CTY

Our Science and Engineering courses bring a variety of science topics to life. By introducing topics not covered in standard science curricula, we build and reinforce your science knowledge. All courses support critical thinking, problem solving, and reasoning, and encourage a real-life, hands-on approach to learning about Earth, space, life sciences, chemistry, and the physical world. Guided by expert CTY science educators, you’ll master science lab kits, perform hands-on experiments using common household objects, participate in dynamic group discussions, or prepare for AP exams.

Newly revised Honors Physics course

Our completely redesigned Honors Physics course features new lessons, conceptual and problem-solving videos, and guiding questions that teach students how to solve each type of problem. Hands-on exploration activities challenge students to solve everyday physics problems from how giant cruise ships stay afloat to how to ship fragile packages without them breaking. Putting their physics knowledge to the test, students compete in our catapult design competition for Furthest Launch and Creative Design awards.

More engaging science enrichment courses!

In the newly revised Inventions in Engineering course, students bring fantasy into reality by creating inventions to solve the problems of favorite fictional characters and the real world alike. A new unit in Introduction to Forensics asks students to evaluate the validity of various kinds of forensic evidence and its impact on the lives of individuals, and to provide recommendations on which types of forensic evidence should be admissible in the criminal justice system. In Household Chemistry, students engage in newly revised activities that help develop their skills in making and recording detailed observations using all 5 senses as they explore states of matter and the role chemistry plays in their daily lives.

Meet our Science and Engineering Instructors