in terms of ecology, why is introducing dead toxic mice to an ecosystem a bad idea?

Answer 1

Because its gonna be all about the Food Chain in an ecosystem in which the mice are placed. The dead mice will attract Scavengers that prey on dead animals such as vultures or even decomposers liek bacteria and even various insects. After they eat the mice they probably will get affected by the toxins placed in the mice before and most likely spread it somehow whether its from maggots eating the carcasses flesh or just any animal taking it in.
The Food Chain will continue into the next set of animals who ate these mice and will pass them on and on untill it'll get somewhat out of control starting poisonous food sources for various other plants and animals and thus affecting various other food chains in the process.

In a nutshell, the toxic mice once eaten will have a snowball affect and spread the toxins.

Answer 2

Mice are eaten by many different types of animals...larger mammals, reptiles, and birds. Even insects will eat the dead mice as they decay (and in fact help them decay). If the mice are toxic then they may cause illness or injury to the animals that have eaten them or the toxic agent can be tracked by the insects to other areas for other animals to be infected.

Answer 3

It depends why they are toxic. If they have lead or mercury in them, the animals that eat them will inherit the heavy metals, possibly leading to birth defects in those animals. If they are poisoned, the animal that eats them would also have the poison in their system.