Animals, erosion and explosions

Clever children have been hard at work making vinegar explosions, designing play equipment for rats and looking for ways to solve the world’s hunger problems.

The Manawatu Science and Technology Fair, which started on Thursday, received 146 entries from primary and secondary school children this year.

Volunteer Barbara Arnold said this year there was a strong interest in themes to do with the Pacific, erosion and experiments involving animals - even though that required an extra step of national ethics approval for animal experiments.

Animal tests included what colour food tray pigs prefer, what food rabbits prefer and what temperature and moon conditions deer are most active in.

‘‘There’s been a rush on soil erosion, one’s about the erosion in the Gorge, that’s new - relating it to something topical,’’ Arnold said.

‘‘It’s so good to see them picking up on something and going with it. They are really enthusiastic.’’

Experiments that could help heal the world included finding the best method to clean up oil after a marine spill and how aquaponics could help feed hungry populations.

Ashhurst School pupil Kaci Whaanga, 12, entered the technology category, designing and making play equipment for her pet rats using nontoxic, easily obtainable, recycled materials such as newspaper, cork, alpaca fibre and flax.

‘‘I used papier mache and made hammocks and houses and bridges so they can get to everything in the cage.

‘‘They really like them, they ate some of it, but it wasn’t harmful at all.’’

Max Miller, 12, designed and made a bike-driven cell phone charger, that was so successful his friends have encouraged him to start a business.

The fair is open for public viewing from 10am to 4pm on Saturday and 10am to noon on Sunday, at Barber Hall, Waldegrave St, Palmerston North.