The researchers studied how toxic chemicals from e-waste build up in different animals in a contaminated pond. They looked at insects, toads, lizards, and birds to see how the chemicals moved through the food chain. They found that the chemicals built up more in birds than in toads or lizards. Insects passed on the chemicals to birds more easily than to other animals. The chemicals also built up more in the land animals than in the water animals. This shows that the way toxic chemicals move through ecosystems on land is different from how they move through water ecosystems.