Meidotchi is an adult. And Ichigotchi is spelled without a T between the I and C. Harutchi is a child.
Here are some more (this is for version 1 and 3 that I remember and probably follows on to version 4):
BABIES
Babies- 5 minute nap 30 minutes after hatching
CHILDREN
Kinakomotchi- Bedtime 8pm, Wakes 9am
Mizutamatchi- Bedtime 8pm, Wakes 8am
Tamatchi- Bedtime 8pm, Wakes 8am
Mohitamatchi- Bedtime 8pm, Wakes 9am
Kuchitamatchi- Bedtime 8pm, Wakes 9am
TEENAGERS
Oniontchi- Bedtime 9pm, Wakes 10am
Patapatatchi- Bedtime 8pm, Wakes 9am
ADULTS
Kurokotchi- Bedtime 10.15pm, Wakes 10am
Mametchi- Bedtime 9pm, Wakes 8am (and same for Mimitchi too)
Tarakotchi- Bedtime 10pm, Wakes 8am
Bunbuntchi- Bedtime 10pm, Wakes 9am
Memetchi- Bedtime 10pm, Wakes 9am
Kuchipatchi- Bedtime 10pm, Wakes 9am
Gozarutchi- Bedtime 11pm, Wakes 10am
Masukutchi/Masktchi- Bedtime 11pm, Wakes 10am
Mimiyoritchi- Bedtime 10pm, Wakes 9am
OLDIES (except Oyajitchi)
Otokitchi and Ojitchi- Bedtime 8pm, Wakes 7am